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University of Helsinki
1.
Wu, Rui.
Heterologous human intrinsic factor expression from probiotic yeast Saccharomyces boulardii.
Degree: Department of Food and Environmental Sciences; Helsingfors universitet, Agrikultur- och forstvetenskapliga fakulteten, Institutionen för livsmedels- och miljövetenskaper, 2017, University of Helsinki
URL: http://hdl.handle.net/10138/231906 
► Saccharomyces cerevisiae var. boulardii is a probiotic strain of the baker’s yeast Saccharomyces cerevisiae. It has a long history of use in treating and preventing…
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▼ Saccharomyces cerevisiae var. boulardii is a probiotic strain of the baker’s yeast Saccharomyces cerevisiae. It has a long history of use in treating and preventing several kinds of diarrhea in human. Recently, scientists have drawn their attentions to use this probiotic yeast as a living drug delivery vehicle to the gastric intestinal tract (GIT). Several distinctive features of S. boulardii such as an optimal growth temperature at 37 ºC and better acidic tolerance enable active recombinant protein expression in harsh conditions. Human intrinsic factor (IF) is a glycoprotein secreted by gastric parietal cells and belongs to vitamin B12 (Cobalamin, Cbl) transport family. The gastric IF gene (GIF) encodes this protein. It is an essential protein for the proper absorption of Cbl in the terminal ileum, lacking of which results in vitamin B12 deficiency, especially common among the elders. This study aims to express active human IF from probiotic S. boulardii that can be combined with vitamin B12 forming B12/IF complex and absorbed by intestinal cells. To achieve these goals, a plasmid pSF-TEF1-TPI1-Blast-GIF was designed for S. boulardii transformation. Verification of recombinant IF was accomplished by SDS-PAGE, Western blotting and peptide sequence mapping by mass spectrometry (MS).
Experimental results indicated that the recombinant IF was not able to be synthesized in useful amount from S. boulardii using plasmid pSF-TEF1-TPI1-Blast-GIF. Transformation of the plasmid carrying GIF sequence brought significant phenotypic and metabolic modification to the host cells. PCR technique was found unsuccessful to verify the presence of correct plasmid, leaving uncertainty whether the correct plasmid was present in the transformants or not. Interestingly, an immunreoactive band at expected size (45 kDa) could be detected with rat polyclonal antibody in Western blotting. This band could be only detected from the supernatant when cells were grown with Cbl supplement, but shown to be exo-1,3-β-glucanase in MS protein sequencing. However, it is still possible that trace amount of recombinant IFs are secreted but cannot be detected due to MS sequencing limitations. Even though there was a contradictory result in Western blotting compared to that of MS sequencing, the excessive secretion of the exo-1,3-β-glucanase which may corrode yeast cell walls, may explain the different phenotype of transformants in comparison to host cells. This study indicated that not all genetic manipulation tools designed for S. cerevisiae are without problems for S. boulardii. More studies need to be carried out for successful heterologous IF protein expression with this probiotic yeast.
Subjects/Keywords: Food Science; Food Science; Food Science
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APA (6th Edition):
Wu, R. (2017). Heterologous human intrinsic factor expression from probiotic yeast Saccharomyces boulardii. (Masters Thesis). University of Helsinki. Retrieved from http://hdl.handle.net/10138/231906
Chicago Manual of Style (16th Edition):
Wu, Rui. “Heterologous human intrinsic factor expression from probiotic yeast Saccharomyces boulardii.” 2017. Masters Thesis, University of Helsinki. Accessed February 28, 2021.
http://hdl.handle.net/10138/231906.
MLA Handbook (7th Edition):
Wu, Rui. “Heterologous human intrinsic factor expression from probiotic yeast Saccharomyces boulardii.” 2017. Web. 28 Feb 2021.
Vancouver:
Wu R. Heterologous human intrinsic factor expression from probiotic yeast Saccharomyces boulardii. [Internet] [Masters thesis]. University of Helsinki; 2017. [cited 2021 Feb 28].
Available from: http://hdl.handle.net/10138/231906.
Council of Science Editors:
Wu R. Heterologous human intrinsic factor expression from probiotic yeast Saccharomyces boulardii. [Masters Thesis]. University of Helsinki; 2017. Available from: http://hdl.handle.net/10138/231906
University of Helsinki
2.
Han, Xiaocui.
Chitin analysis of insects (mealworm and cricket).
Degree: Department of Food and Environmental Sciences; Helsingfors universitet, Agrikultur- och forstvetenskapliga fakulteten, Institutionen för livsmedels- och miljövetenskaper, 2018, University of Helsinki
URL: http://hdl.handle.net/10138/233314
► The literature review dealt with the chemical and physical properties of chitin polymer and its degradation product glucosamine. Particular emphasis was given to studies on…
(more)
▼ The literature review dealt with the chemical and physical properties of chitin polymer and its degradation product glucosamine. Particular emphasis was given to studies on the analytical methods of determination of chitin from various products including gravimetrical, spectrophotometric and chromatographic methods.
The aim of this study was to optimize an analytical method to determine insect chitin and to apply the method to quantify chitin in whole insects and their soluble protein fractions. Two species of insects were selected: mealworm larvae (Tenebrio molitor) and cricket (Acheta domesticus). Whole insects and their protein fractions were treated with alkaline to remove protein. Chitin in de-proteined insect material was then hydrolysed into glucosamine using 6M HCl. Glucosamine from the hydrolysate was determined using chromatographic and spectrophotometric methods, where chromatographic method was optimized and validated.
UPLC-FLR method was specific for glucosamine and the UPLC system could separate two target peaks (glucosamine isomers: α and β). Glucosamine content was calculated using a calibration curve which showed excellent linearity in range 0.0033~24.0 ng/inj. with the determination coefficient more than 0.999 during the study period. The instrumental limit of detection and limit of quantification were 0.00095 ng/inj. (2 µL) and 0.0033 ng/inj. (7 µL), indicating a satisfied sensitivity. Recovery of glucosamine spiked to sample matrix (de-proteined cricket flour) following chitin hydrolysis was not satisfactory (~75%) using HPLC-FLR method, which indicated that spectrophotometric method gave chitin amount closer to the true value due to a higher recovery (>90%). Major findings on chitin amount was ~5% on dry matter basis in both mealworm and cricket. A small percentage of chitin was found in insect protein fractions extracted by 0.1M NaCl.
Subjects/Keywords: Food Science; Food Science; Food Science
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APA (6th Edition):
Han, X. (2018). Chitin analysis of insects (mealworm and cricket). (Masters Thesis). University of Helsinki. Retrieved from http://hdl.handle.net/10138/233314
Chicago Manual of Style (16th Edition):
Han, Xiaocui. “Chitin analysis of insects (mealworm and cricket).” 2018. Masters Thesis, University of Helsinki. Accessed February 28, 2021.
http://hdl.handle.net/10138/233314.
MLA Handbook (7th Edition):
Han, Xiaocui. “Chitin analysis of insects (mealworm and cricket).” 2018. Web. 28 Feb 2021.
Vancouver:
Han X. Chitin analysis of insects (mealworm and cricket). [Internet] [Masters thesis]. University of Helsinki; 2018. [cited 2021 Feb 28].
Available from: http://hdl.handle.net/10138/233314.
Council of Science Editors:
Han X. Chitin analysis of insects (mealworm and cricket). [Masters Thesis]. University of Helsinki; 2018. Available from: http://hdl.handle.net/10138/233314
University of Helsinki
3.
Wang, Cong.
Comparison of some chemical and physical characteristics of Pectoralis major muscles between Wooden Breast affected and Normal broilers.
Degree: Department of Food and Environmental Sciences; Helsingfors universitet, Agrikultur- och forstvetenskapliga fakulteten, Institutionen för livsmedels- och miljövetenskaper, 2016, University of Helsinki
URL: http://hdl.handle.net/10138/163652
► Recently, an unknown myopathy has been observed in some Finnish broiler Pectoralis major muscle for the past 3 years and similar breast muscle defect have…
(more)
▼ Recently, an unknown myopathy has been observed in some Finnish broiler Pectoralis major muscle for the past 3 years and similar breast muscle defect have been found in several other countries as well. Wooden Breast is the term to describe this abnormality due to its macroscopically visible hard, bulging and pale area in the caudal part of the fillet.
This study aims to compare and measure some physical properties and chemical composition differences between Wooden Breast and Normal broiler breast muscle.
32 breast fillets of 38 days old Rose 508 broilers were sacrificed at the university experiment premises for evaluation. 20 breasts muscle were Wooden Breast affected, and the other 12 macroscopically Normal breast muscles served as Normal. In this experiment, measurement of sample physical properties (drip loss, cook loss, compression test, and Allo-Kramer shear force) and chemical composition (moisture, protein, and collagen content) were conducted.
As for the results, Wooden Breast had lower protein content and higher moisture content (P<0.05) than Normal; Wooden Breast had higher drip and cooking losses (P<0.05) than Normal; Wooden and Normal breast muscles did not differ in the initial and the ultimate pH; Wooden Breasts had similar compression (24h) and shear force (cooked) results compared to Normal breast (P>0.05); No quantitative difference in total or soluble collagen were detected (P>0.05).
Subjects/Keywords: Food Science; Food Science; Food Science
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APA (6th Edition):
Wang, C. (2016). Comparison of some chemical and physical characteristics of Pectoralis major muscles between Wooden Breast affected and Normal broilers. (Masters Thesis). University of Helsinki. Retrieved from http://hdl.handle.net/10138/163652
Chicago Manual of Style (16th Edition):
Wang, Cong. “Comparison of some chemical and physical characteristics of Pectoralis major muscles between Wooden Breast affected and Normal broilers.” 2016. Masters Thesis, University of Helsinki. Accessed February 28, 2021.
http://hdl.handle.net/10138/163652.
MLA Handbook (7th Edition):
Wang, Cong. “Comparison of some chemical and physical characteristics of Pectoralis major muscles between Wooden Breast affected and Normal broilers.” 2016. Web. 28 Feb 2021.
Vancouver:
Wang C. Comparison of some chemical and physical characteristics of Pectoralis major muscles between Wooden Breast affected and Normal broilers. [Internet] [Masters thesis]. University of Helsinki; 2016. [cited 2021 Feb 28].
Available from: http://hdl.handle.net/10138/163652.
Council of Science Editors:
Wang C. Comparison of some chemical and physical characteristics of Pectoralis major muscles between Wooden Breast affected and Normal broilers. [Masters Thesis]. University of Helsinki; 2016. Available from: http://hdl.handle.net/10138/163652
University of Helsinki
4.
Ababei, Cristina-Georgiana.
Influence of Wooden Breast myopathy on sarcomere length and tensile strength in commercial chicken breast.
Degree: Department of Food and Environmental Sciences; Helsingfors universitet, Agrikultur- och forstvetenskapliga fakulteten, Institutionen för livsmedels- och miljövetenskaper, 2016, University of Helsinki
URL: http://hdl.handle.net/10138/168209
► Wooden Breast is a myopathy seen on chicken breast muscles in the last years, causing economic losses. It is associated with hardness and paleness of…
(more)
▼ Wooden Breast is a myopathy seen on chicken breast muscles in the last years, causing economic losses. It is associated with hardness and paleness of the muscle, necrosis, fibrosis and macrophage infiltration. The aim of this study was to investigate the differences in sarcomere length and tensile strength between normal and Wooden Breast in chicken. For the sarcomere length measurements 20 unaffected chicken breasts and 21 Wooden Breasts were used. For half of each group electrical stimulation was applied. Sarcomere length was measured in four different locations of each breast: cranial and medial area, surface and depth. The tensile test experiment involved three experimental groups, with 20 samples for each group: unaffected, with focal lesion and with diffuse lesion. Samples were cut from the surface layer of cranial and medial area of every chicken breast, both on longitudinal and transversal direction of the muscle fibers.
Results showed that Wooden Breast syndrome has a significant effect on sarcomere length, leading to increased lengths in the affected muscles compared with the normal muscles (p<0.05). There was less lengthening of the sarcomere as result of electrical stimulation in WB muscles compared with normal chicken breasts (p<0.05). The difference in sarcomere length between WB and Normal was smaller in the surface layer of the muscle in comparison with the depth layer. There were no significant difference between the mean values of tensile strength in Normal samples and Focal WB samples, but significantly higher values in Diffuse WB samples (p<0.0001). The Diffuse samples yielded significant higher tensile strength when they were stretched parallel with muscle fiber direction, compared with cross-sectional direction of stretching (p<0.05). In the Diffuse cases the cranial area had increased tensile strength compared with the medial area, indicating an increased level of WB severity in the cranial area compared with medial area.
Subjects/Keywords: Food Science; Food Science; Food Science
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APA (6th Edition):
Ababei, C. (2016). Influence of Wooden Breast myopathy on sarcomere length and tensile strength in commercial chicken breast. (Masters Thesis). University of Helsinki. Retrieved from http://hdl.handle.net/10138/168209
Chicago Manual of Style (16th Edition):
Ababei, Cristina-Georgiana. “Influence of Wooden Breast myopathy on sarcomere length and tensile strength in commercial chicken breast.” 2016. Masters Thesis, University of Helsinki. Accessed February 28, 2021.
http://hdl.handle.net/10138/168209.
MLA Handbook (7th Edition):
Ababei, Cristina-Georgiana. “Influence of Wooden Breast myopathy on sarcomere length and tensile strength in commercial chicken breast.” 2016. Web. 28 Feb 2021.
Vancouver:
Ababei C. Influence of Wooden Breast myopathy on sarcomere length and tensile strength in commercial chicken breast. [Internet] [Masters thesis]. University of Helsinki; 2016. [cited 2021 Feb 28].
Available from: http://hdl.handle.net/10138/168209.
Council of Science Editors:
Ababei C. Influence of Wooden Breast myopathy on sarcomere length and tensile strength in commercial chicken breast. [Masters Thesis]. University of Helsinki; 2016. Available from: http://hdl.handle.net/10138/168209
University of Helsinki
5.
Ercili-Cura, Dilek.
Structure modification of milk protein gels by enzymatic cross-linking.
Degree: Department of Food and Environmental Sciences; VTT, Technical Research Center of Finland, 2012, University of Helsinki
URL: http://hdl.handle.net/10138/37398
► Proteins are the structural building blocks of fermented dairy products such as yoghurt. The nature of the protein-protein interactions and the structure of the macromolecular…
(more)
▼ Proteins are the structural building blocks of fermented dairy products such as yoghurt. The nature of the protein-protein interactions and the structure of the macromolecular matrices they form determine the textural and water holding properties of a gel. In this study, the potential of enzymatic cross-linking in modification of acid-induced milk protein gel structures was studied by using the oxidative enzymes laccase and tyrosinase as well as the acyltransferase transglutaminase. The efficiency of the cross-linking enzymes with dissimilar reaction mechanisms in modification of milk proteins at various colloidal (milk or caseinate) or molecular (native, unfolded) states was investigated. Effects of enzymatically formed inter-molecular covalent bonds on the gel formation dynamics and the textural and water holding properties of acid-induced milk protein gels were elucidated.
The results presented in this study have shown that enzymatic cross-linking, even with the oxidative enzymes tyrosinase and laccase, alters the mechanical properties of acid-induced milk protein gels. However, the knowledge on the mode of action of these enzymes on proteins should be further elucidated in order to be able to exploit them as structure-engineering tools with maximum efficiency. Comparison of the action of tyrosinase and transglutaminase in milk showed that even rather similar extent of inter-molecular covalent linkages did not necessarily result in similar mechanical properties in final acid-induced gels. It was concluded that it is not solely the introduced covalent links but also the preceding impacts on colloidal interactions by physical means which determine the actual effect of cross-linking on the final product attributes. In this thesis, the potential of one oxidative enzyme, T. reesei tyrosinase (TrT), was demonstrated for the creation of intra-micellarly linked casein particles, similarly to TG. In the future, it will be necessary to determine the physicochemical properties of TrT-induced casein particles as compared to the TG-induced casein particles. Furthermore, in raw milk, TrT was the only enzyme able to increase the gel firmness. This makes TrT a potential enzyme for use in raw milk-based products such as cheese. Finally, elucidation of altered aggregation dynamics for cross-linked protein particles will help to determine the optimum production parameters in order to tailor protein gels for improved product characteristics.
Hapanmaitotuotteissa kuten jogurtissa proteiinit muodostavat verkostorakenteen, jossa proteiinien väliset vuorovaikutukset ovat tärkeimpiä aistittavaan rakenteeseen ja vedensidontaominaisuuksiin vaikuttavia tekijöitä. Väitöskirjatutkimuksessa selvitettiin proteiinin entsymaattisen ristisilloituksen soveltuvuutta hapanmaitogeelien rakenteenmuokkaukseen. Tutkimuksessa käytettiin kahta hapettavaa entsyymiä, lakkaasia ja tyrosinaasia, sekä transglutaminaasia. Mekanismiltaan toisistaan eroavien entsyymien vaikutusta proteiinien ristisilloittamiseen tutkittiin maidossa sellaisenaan ja…
Subjects/Keywords: food Science; food Science
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APA (6th Edition):
Ercili-Cura, D. (2012). Structure modification of milk protein gels by enzymatic cross-linking. (Doctoral Dissertation). University of Helsinki. Retrieved from http://hdl.handle.net/10138/37398
Chicago Manual of Style (16th Edition):
Ercili-Cura, Dilek. “Structure modification of milk protein gels by enzymatic cross-linking.” 2012. Doctoral Dissertation, University of Helsinki. Accessed February 28, 2021.
http://hdl.handle.net/10138/37398.
MLA Handbook (7th Edition):
Ercili-Cura, Dilek. “Structure modification of milk protein gels by enzymatic cross-linking.” 2012. Web. 28 Feb 2021.
Vancouver:
Ercili-Cura D. Structure modification of milk protein gels by enzymatic cross-linking. [Internet] [Doctoral dissertation]. University of Helsinki; 2012. [cited 2021 Feb 28].
Available from: http://hdl.handle.net/10138/37398.
Council of Science Editors:
Ercili-Cura D. Structure modification of milk protein gels by enzymatic cross-linking. [Doctoral Dissertation]. University of Helsinki; 2012. Available from: http://hdl.handle.net/10138/37398
6.
Neethling, Jeannine.
Impact of season on the composition and quality of male and female blesbok (Damaliscus pygargus phillipsi) muscles.
Degree: MSc, Food Science, 2012, Stellenbosch University
URL: http://hdl.handle.net/10019.1/71826
► ENGLISH ABSTRACT: The objective of this study was to investigate the impact of season on the composition and quality of male and female blesbok (Damaliscus…
(more)
▼ ENGLISH ABSTRACT: The objective of this study was to investigate the impact of season on the composition and quality
of male and female blesbok (Damaliscus pygargus phillipsi) muscles (Longissimus dorsi, Biceps
femoris, Semimembranosus, Semitendinosus, Infraspinatus and Supraspinatus). The latter was
quantified on the chemical composition (moisture, protein, fat and ash contents), fatty acid profile,
mineral composition and physical attributes (pH, colour, drip and cooking loss, water holding
capacity and tenderness) of the selected muscles.
All of the blesbok muscles had higher (p<0.01) mean protein contents (20.6 g.100 g-1 to
23.1 g.100 g-1) when the plane of nutrition was believed to be higher (spring of 2009). A strong
negative correlation (r = – 0.82; p<0.01) existed between the moisture and protein contents of the
blesbok muscles. The Longissimus dorsi muscle had the highest (p<0.01) mean intramuscular fat
content (3.4 g.100 g-1) when the plane of nutrition was higher. The chemical composition of the
Longissimus dorsi, Biceps femoris, Semitendinosus and forequarter muscles (Infraspinatus and
Supraspinatus) was affected least by the seasonal differences in the plane of nutrition and activity
levels of the blesbok at the study area. However, season had a larger impact on the chemical
composition of the Semimembranosus muscle.
Season did not have a significant impact on the fatty acid profile of blesbok muscles, but
the difference in the fatty acid profiles between male and female muscles was significant. A
Principal Component Analysis (PCA) bi-plot indicated that female blesbok muscles were
associated with a higher saturated fatty acid (SFA) and mono-unsaturated fatty acid (MUFA)
content. Male blesbok muscles had higher (p<0.01) proportions of total polyunsaturated fatty acids
(PUFA) (40.15 ± 5.39) and polyunsaturated to saturated fatty acid ratios (P:S) (0.85 ± 0.18), in
comparison to female muscles (27.18 ± 8.04 and 0.54 ± 0.20, respectively). Differences in the
anatomical locations of the selected blesbok muscles furthermore influenced the fatty acid profiles.
The less active Longissimus dorsi muscle had higher (p<0.05) total PUFA (38.34 ± 8.62), total
omega-6 (ω6) PUFA (34.46 ± 7.83), total ω3 PUFA (3.44 ± 0.84) and P:S (0.85 ± 0.24) contents, in
comparison to the Infraspinatus muscle (28.96 ± 8.65, 26.23 ± 7.86, 2.31 ± 0.70 and 0.56 ± 0.19,
respectively) and Supraspinatus muscle (28.85 ± 9.23, 26.05 ± 8.24, 2.28 ± 0.76 and 0.55 ± 0.21,
respectively). The hindquarter muscles (Biceps femoris, Semimembranosus and Semitendinosus)
had intermediate fatty acid content.
Season had an impact on the calcium and zinc contents of blesbok muscles. The calcium
content was higher (p<0.05) in the muscles of the animals harvested in spring (6.92 ± 1.94)
compared to winter (5.61 ± 1.79). The zinc content was higher (p<0.05) in the muscles of male
blesbok harvested in winter (4.04 ± 1.70) compared to spring (3.41 ± 1.67). The mineral
composition was furthermore significantly different between…
Advisors/Committee Members: Hoffman, L. C., Britz, T. J., Stellenbosch University. Faculty of AgriSciences. Dept. of Food Science..
Subjects/Keywords: Food science; Food Science
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APA (6th Edition):
Neethling, J. (2012). Impact of season on the composition and quality of male and female blesbok (Damaliscus pygargus phillipsi) muscles. (Masters Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/71826
Chicago Manual of Style (16th Edition):
Neethling, Jeannine. “Impact of season on the composition and quality of male and female blesbok (Damaliscus pygargus phillipsi) muscles.” 2012. Masters Thesis, Stellenbosch University. Accessed February 28, 2021.
http://hdl.handle.net/10019.1/71826.
MLA Handbook (7th Edition):
Neethling, Jeannine. “Impact of season on the composition and quality of male and female blesbok (Damaliscus pygargus phillipsi) muscles.” 2012. Web. 28 Feb 2021.
Vancouver:
Neethling J. Impact of season on the composition and quality of male and female blesbok (Damaliscus pygargus phillipsi) muscles. [Internet] [Masters thesis]. Stellenbosch University; 2012. [cited 2021 Feb 28].
Available from: http://hdl.handle.net/10019.1/71826.
Council of Science Editors:
Neethling J. Impact of season on the composition and quality of male and female blesbok (Damaliscus pygargus phillipsi) muscles. [Masters Thesis]. Stellenbosch University; 2012. Available from: http://hdl.handle.net/10019.1/71826
Stellenbosch University
7.
Kikine, Tshepo Neo Ferdinard.
Profiling of potential pathogens from Plankenburg river water used for the irrigation of fresh produce.
Degree: MSc Food Sc, Food Science, 2011, Stellenbosch University
URL: http://hdl.handle.net/10019.1/18095
► ENGLISH ABSTRACT: The increased consumption of fresh produce has been shown to be related to increases in foodborne disease outbreaks and these have in many…
(more)
▼ ENGLISH ABSTRACT: The increased consumption of fresh produce has been shown to be related to increases in
foodborne disease outbreaks and these have in many cases been ascribed directly to carry-over of
pathogens from contaminated irrigation water. In South Africa, rivers are the main source of
irrigation water but many have been found to be unsuitable for irrigation of fresh produce because
of the unacceptably high levels of faecal contamination.
The main aim of this study was to do a baseline evaluation of the microbiological quality of
the Plankenburg and Eerste Rivers and to determine which bacterial contaminants are present.
Two sampling sites were selected for the Plankenburg (Plank-1 and -3) and one for the Eerste
River (Eerste-1). The microbiological analysis included aerobic colony count (ACC), aerobic and
anaerobic sporeformers, Staphylococcus, Salmonella, Listeria, enterococci, coliforms, faecal
coliforms and E. coli using standard methods. The faecal contamination levels for both rivers
exceeded the DWAF and WHO guidelines of <1 000 E. coli per 100 mL water for irrigation of fresh
produce intended to be consumed raw. The Plankenburg River sites always had higher coliform
contamination levels (1 200 - 13 000 000 MPN per 100 mL water) than the Eerste River site (230 -
79 000 MPN per 100 mL water). There was also a high incidence of index organisms including
Salmonella, Staphylococcus, Listeria and endosporeformers. The isolation of intestinal
enterococci suggested the presence of potential pathogens that can cause disease outbreaks.
The baseline data also showed large variations in microbial loads over the 15 month study with the
faecal coliform counts ranging for Plank-1 from 1 200 to 7 000 000 MPN.100mL-1, Plank-3 from 10
to 460 000 MPN.100mL-1 and Eerste-1 from 28 to 79 000 MPN.100mL-1. The water temperatures
at all three sites ranged from 12.1° to 21.7°C with COD values in most cases below 100 mg.L-1.
As the baseline study showed large variations in microbial loads over the 15 month study
period an assessment using the Colilert-18 system of the weekly, daily and hourly variations, for 6
weeks over a period of 4 months was conducted at site Plank-2. This site was specifically used as
it is an irrigation source point for nearby fresh produce farmers and is about 2 km further
downstream from an informal settlement. The weekly variation trend for total coliforms (TC)
showed a decrease over the entire sampling period with the highest count of 3 200 000 MPN.100
mL-1 during the warmer period. The E.coli (Ec) counts showed a similar trend with the highest
count of 440 000 MPN.100 mL-1 also in March. The daily variation trends were the same for both
the TC and Ec and counts found to increase from Monday to Thursday followed by a decrease to
Sunday. The highest counts were on Thursday with average TC and Ec counts of 1 900 000 and
160 000 MPN.100 mL-1, respectively. The hourly variation trends were similar for both TC and Ec
with counts increasing from 06h00 to 12h00 followed by a…
Advisors/Committee Members: Britz, T. J., Sigge, G. O., Stellenbosch University. Faculty of AgriSciences. Dept. of Food Science..
Subjects/Keywords: Food science; Food Science
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APA (6th Edition):
Kikine, T. N. F. (2011). Profiling of potential pathogens from Plankenburg river water used for the irrigation of fresh produce. (Masters Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/18095
Chicago Manual of Style (16th Edition):
Kikine, Tshepo Neo Ferdinard. “Profiling of potential pathogens from Plankenburg river water used for the irrigation of fresh produce.” 2011. Masters Thesis, Stellenbosch University. Accessed February 28, 2021.
http://hdl.handle.net/10019.1/18095.
MLA Handbook (7th Edition):
Kikine, Tshepo Neo Ferdinard. “Profiling of potential pathogens from Plankenburg river water used for the irrigation of fresh produce.” 2011. Web. 28 Feb 2021.
Vancouver:
Kikine TNF. Profiling of potential pathogens from Plankenburg river water used for the irrigation of fresh produce. [Internet] [Masters thesis]. Stellenbosch University; 2011. [cited 2021 Feb 28].
Available from: http://hdl.handle.net/10019.1/18095.
Council of Science Editors:
Kikine TNF. Profiling of potential pathogens from Plankenburg river water used for the irrigation of fresh produce. [Masters Thesis]. Stellenbosch University; 2011. Available from: http://hdl.handle.net/10019.1/18095
Stellenbosch University
8.
Hanekom, Evette.
Chemical, sensory and consumer profiling of a selection of South African Chenin blanc wines produced from bush vines.
Degree: MScFoodSc, Food Science, 2012, Stellenbosch University
URL: http://hdl.handle.net/10019.1/71812
► ENGLISH ABSTRACT: Twenty five commercial Chenin blanc wines produced solely from bush vine vineyards and including three vintages, three styles and five production areas, were…
(more)
▼ ENGLISH ABSTRACT: Twenty five commercial Chenin blanc wines produced solely from bush vine vineyards and including three vintages, three styles and five production areas, were sourced for this study. Descriptive sensory analysis (DSA) and chemical analyses including GC-FID (gas chromatography fitted with a flame ionisation detector) and FTMIR (Fourier transform mid-infrared) spectroscopy were employed to establish the sensory and chemical characteristics, whereas consumer tests were conducted to determine consumer perception and liking of bush vine Chenin blanc wines. DSA (a profiling technique) was also compared to the sorting task (a classification technique) with a description assignment to evaluate the sorting task’s ability to profile wines.
According to the results of DSA, the wines separated into two groups. One group associated with sensory attributes which can be considered indicative of the Fresh and Fruity Chenin blanc style. The other group associated with sensory attributes which can be considered indicative of the Rich and Ripe style of Chenin blanc. No separation between the wooded and unwooded Rich and Ripe styles was apparent.
According to the results of the chemical analyses, the wines also separated into two groups. This separation seemed to be caused by vintage and the chemical changes associated with ageing as the wines from the youngest vintage (2010) was strongly associated with high levels of esters and malic acid. The older wines were situated farthest away from these attributes indicating low concentrations. When comparing the results from the sorting task and DSA, it could be seen that similar wine style groupings formed, indicating that DSA can also be regarded as an effective tool when categorising wines. The differences in the positioning of some of the wines and attributes on the DSA multivariate plots and the sorting task plots could be attributed to the difference in panels used. The sorting task was conducted using an expert panel with persons illustrating significant technical knowledge of Chenin blanc wines. Experience, exposure and technical knowledge tend to establish a common language amongst wine experts which could have caused the expert panel to perceive some wines differently when comparing the results of the latter panel to that of the trained panel. DSA was found to remain the most effective method for establishing a comprehensive sensory profile.
Consumer analyses showed that regular white wine drinkers prefer the unwooded styles (Fresh and Fruity and Rich and Ripe unwooded) of Chenin blanc more than the wooded style. It was also found that consumers with a higher level of objective wine knowledge tend to associate the terms ‘bush vine’ and ‘old bush vine’ with the Rich and Ripe style of Chenin blanc, whereas consumers with a lower level of objective wine knowledge associated ‘old bush vine’ with the Fresh and Fruity style. Since all the wines used in the consumer analysis were produced from old bush vines, it is evident that consumer education on the impact of bush…
Advisors/Committee Members: Muller, M., Nieuwoudt, H. H., Tredoux, A. G. J., Stellenbosch University. Faculty of AgriSciences. Dept. of Food Science..
Subjects/Keywords: Food science; Food Science
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APA (6th Edition):
Hanekom, E. (2012). Chemical, sensory and consumer profiling of a selection of South African Chenin blanc wines produced from bush vines. (Masters Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/71812
Chicago Manual of Style (16th Edition):
Hanekom, Evette. “Chemical, sensory and consumer profiling of a selection of South African Chenin blanc wines produced from bush vines.” 2012. Masters Thesis, Stellenbosch University. Accessed February 28, 2021.
http://hdl.handle.net/10019.1/71812.
MLA Handbook (7th Edition):
Hanekom, Evette. “Chemical, sensory and consumer profiling of a selection of South African Chenin blanc wines produced from bush vines.” 2012. Web. 28 Feb 2021.
Vancouver:
Hanekom E. Chemical, sensory and consumer profiling of a selection of South African Chenin blanc wines produced from bush vines. [Internet] [Masters thesis]. Stellenbosch University; 2012. [cited 2021 Feb 28].
Available from: http://hdl.handle.net/10019.1/71812.
Council of Science Editors:
Hanekom E. Chemical, sensory and consumer profiling of a selection of South African Chenin blanc wines produced from bush vines. [Masters Thesis]. Stellenbosch University; 2012. Available from: http://hdl.handle.net/10019.1/71812
Stellenbosch University
9.
Geldenhuys, Greta.
Egyptian goose (Alopochen aegyptiacus) : sensory, biochemical and physical meat quality as affected by gender, diet and ageing.
Degree: Animal Sciences, 2014, Stellenbosch University
URL: http://hdl.handle.net/10019.1/95871
► Thesis (PhD(Food Sc)) – Stellenbosch University, 2014.
ENGLISH ABSTRACT: In Southern Africa, the hunting of wildfowl species has increased considerably in the past few years. Crop…
(more)
▼ Thesis (PhD(Food Sc)) – Stellenbosch University, 2014.
ENGLISH ABSTRACT: In Southern Africa, the hunting of wildfowl species has increased considerably in the past few years. Crop farmers incur major financial losses due to the feeding activities of Egyptian geese (Alopochen aegyptiacus); consequently a large number of geese are hunted in an attempt to reduce the damage caused. With the current absence of scientific information baseline research investigating the meat quality of this species is essential.
The sensory profile of Egyptian goose meat was found to be very distinct in relation to the characteristics of other well-known fowl species. It has very strong game aroma and flavour attributes with a prominent metallic aftertaste. The intense aroma and flavour notes were linked to the substantially higher iron content, as well as the high overall polyunsaturated fatty acid content as revealed by chemical profiling. The trained sensory panel also found the meat to be very tough (high shear force) compared to the other species.
To identify the factors which may affect the overall consistency of the meat quality, the influence of three main effects namely; season (grain vs. non-grain diet), gender and portion was investigated. This revealed that season had the largest effect and harvesting periods should therefore be considered. The main issue is the higher intramuscular fat (IMF) content in winter (July), as well as the substantial difference in the fatty acid profiles of the two seasons. The forage vs. grain based diets during certain periods of the year leads to variation in the content of key fatty acids in the meat i.e. oleic acid, linoleic acid and α-linolenic acid. In winter, the meat had a characteristic, prominent game and metallic aroma while the summer (November) profile was governed by “sweet-oily-duck” and beef-like sensory notes. The fatty acid differences also result in variation between the omega 6 to omega 3 ratios of the seasons; the portions from winter are within the recommendations (ratio<5) and those from summer not. Regarding gender, the females had a lower carcass yield but higher IMF content. The female breast portion was also more tender (lower shear force).
In attempting to elucidate the toughness of the meat, possible causes have been proposed. The pH decline in the pectoralis muscle occurs quite rapidly and it is possible that the high rigor temperature (>20 °C) may contribute to the increased toughness. Regardless of the proteolytic enzyme activity during the rigor period, the meat is still tough at 36 h post mortem and the proteolytic contribution may be overshadowed by the background toughness, i.e. the connective tissue content and fibre structure. The latter was confirmed when the breast portions were aged for 14 days and no change (decline) in the shear force values was observed even though myofibrillar degradation did occur (during ageing). Given the lack of a decline in the shear force, the aging of Egyptian goose meat as a means of improving the overall toughness cannot be…
Advisors/Committee Members: Hoffman, Louwrens Christiaan, Muller, M., Stellenbosch University. Faculty of AgriSciences. Dept. of Animal Sciences..
Subjects/Keywords: Food science; Dissertations – Food science
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APA (6th Edition):
Geldenhuys, G. (2014). Egyptian goose (Alopochen aegyptiacus) : sensory, biochemical and physical meat quality as affected by gender, diet and ageing. (Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/95871
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Geldenhuys, Greta. “Egyptian goose (Alopochen aegyptiacus) : sensory, biochemical and physical meat quality as affected by gender, diet and ageing.” 2014. Thesis, Stellenbosch University. Accessed February 28, 2021.
http://hdl.handle.net/10019.1/95871.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Geldenhuys, Greta. “Egyptian goose (Alopochen aegyptiacus) : sensory, biochemical and physical meat quality as affected by gender, diet and ageing.” 2014. Web. 28 Feb 2021.
Vancouver:
Geldenhuys G. Egyptian goose (Alopochen aegyptiacus) : sensory, biochemical and physical meat quality as affected by gender, diet and ageing. [Internet] [Thesis]. Stellenbosch University; 2014. [cited 2021 Feb 28].
Available from: http://hdl.handle.net/10019.1/95871.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Geldenhuys G. Egyptian goose (Alopochen aegyptiacus) : sensory, biochemical and physical meat quality as affected by gender, diet and ageing. [Thesis]. Stellenbosch University; 2014. Available from: http://hdl.handle.net/10019.1/95871
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Stellenbosch University
10.
Schoeman, Nika Anna.
Prevalence, characterisation and potential origin of Escherichia coli found in surface and ground waters utilized for irrigation of fresh produce.
Degree: MSc Food Sc, Food Science, 2013, Stellenbosch University
URL: http://hdl.handle.net/10019.1/79801
► ENGLISH ABSTRACT: Over the past two decades, there has been an increase in the use of water sources for irrigation, as well as an increase…
(more)
▼ ENGLISH ABSTRACT: Over the past two decades, there has been an increase in the use of water sources for
irrigation, as well as an increase in Escherichia coli outbreaks linked to fresh produce. The full
extent and type of E. coli contamination present in natural water sources is unknown and the
contamination sources have also not been confirmed. The aim of this study was to enumerate
and characterise E. coli from both irrigation water and potential contamination source sites.
Total coliform and E. coli counts found in contamination source sites were
as high as log 7.114 and log 6.912 MPN.100 mL-1, respectively. Total coliform and E. coli counts
for irrigation sites were lower, with maximum counts of log 5.788 and
log 5.768 MPN.100 mL-1, respectively. It was found that more than one third (5/14 = 35.71%) of
the irrigation sites had E. coli counts exceeding the guidelines (<1 000 counts.100 mL-1) for ‘safe’
irrigation water for fresh produce (<1 000 counts.100 mL-1) as set by the Department of Water
Affairs (DWA) and World Health Organisation (WHO), making the water unsuitable for the
irrigation of fresh produce.
Phylogenetic subgroups (A0, A1, B1, B22, B23, D1 and D2) and the MALDI Biotyper system
(PCA dendrogram) were used to create a fingerprint of each E. coli isolated from the environment.
These were then used to link E. coli strains from irrigation water to their most probable
contamination origin. Escherichia coli population structure was found in this study, to be better
suited for linking E. coli strains from irrigation water to their most likely source, than just applying
the phylogenetic grouping. The MALDI Biotyper data in combination with the phylogenetic
subgroup assignment was then used to group similar strains and link E. coli from irrigation water
to their contamination sources by comparing population structures. Strains isolated from surface
and groundwater showed similar distribution patterns, but groundwater strains showed a
population structure more indicative of porcine and bovine origin, while surface water showed
population characteristics which could not be used to make conclusive links between the
irrigation water and suspected contamination sources. When investigating the population structures of individual sample sites, it was found that
phylogenetic subgroups A0, A1 and B1 frequently made up the bulk of the E. coli population. It
was also found that linking individual irrigation sites to contamination sources was successful, as
irrigation site Berg-2 was found to have a similar population structure to contamination source
site Plank-1 which represents human pollution from an informal settlement. This led to the conclusion that Berg-2 was being contaminated by human pollution, most probably from an
informal settlement. Upon further investigation it was found that Berg-2 is downstream of an
informal settlement, proving that E. coli population structure is a successful means of microbial
source tracking (MST).
Virulence factors of the 153 E. coli isolated…
Advisors/Committee Members: Britz, T. J., Sigge, G. O., Lamprecht, Corne, Stellenbosch University. Faculty of AgriSciences. Dept. of Food Science..
Subjects/Keywords: Food science; Food Science
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Manager
APA (6th Edition):
Schoeman, N. A. (2013). Prevalence, characterisation and potential origin of Escherichia coli found in surface and ground waters utilized for irrigation of fresh produce. (Masters Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/79801
Chicago Manual of Style (16th Edition):
Schoeman, Nika Anna. “Prevalence, characterisation and potential origin of Escherichia coli found in surface and ground waters utilized for irrigation of fresh produce.” 2013. Masters Thesis, Stellenbosch University. Accessed February 28, 2021.
http://hdl.handle.net/10019.1/79801.
MLA Handbook (7th Edition):
Schoeman, Nika Anna. “Prevalence, characterisation and potential origin of Escherichia coli found in surface and ground waters utilized for irrigation of fresh produce.” 2013. Web. 28 Feb 2021.
Vancouver:
Schoeman NA. Prevalence, characterisation and potential origin of Escherichia coli found in surface and ground waters utilized for irrigation of fresh produce. [Internet] [Masters thesis]. Stellenbosch University; 2013. [cited 2021 Feb 28].
Available from: http://hdl.handle.net/10019.1/79801.
Council of Science Editors:
Schoeman NA. Prevalence, characterisation and potential origin of Escherichia coli found in surface and ground waters utilized for irrigation of fresh produce. [Masters Thesis]. Stellenbosch University; 2013. Available from: http://hdl.handle.net/10019.1/79801
11.
Zhong, Amy.
Product Development Considerations for a Nutrient Rich Bar Using Cricket (Acheta domesticus) Protein.
Degree: 2017, California State University, Long Beach
URL: http://pqdtopen.proquest.com/#viewpdf?dispub=10262776
► Insect protein has recently gained attention as an alternate protein source for humans as it is regarded as a sustainable source of protein that…
(more)
▼ Insect protein has recently gained attention as an alternate protein source for humans as it is regarded as a sustainable source of protein that is nutritionally comparable to traditional livestock. The objective of this study was to assess the acceptability of a protein bar supplemented with cricket protein. A bar composed of 7.5% cricket powder was compared against a market alternative in a evaluation, food action rating scale (FACT), paired-preference test, and a triangle test. Subjects rated the market bar higher than the cricket bar for appearance (6.59±1.92; 6.32±2.05), color (6.37±1.92; 6.22±1.84), flavor (6.41±1.86; 5.46±2.53), aroma (6.25±1.50; 5.75±1.82), texture (6.79±1.65; 5.95±1.93), and overall acceptability (6.67±1.67; 5.75±2.07). Flavor (<i>p</i>=0.16), texture (<i>p</i>=0.003), and overall acceptability (<i>p</i>=0.004) were rated significantly lower in the cricket bar. Moreover, more subjects indicated in their scores that they would eat the market bar (5.70±1.64) more frequently than the insect bar (4.66±2.14). Texture, appearance, aroma, and flavor were all significantly associated (<i>p</i><0.05) with overall acceptability. The majority (61%) of subjects preferred the market bar to the insect alternative. Additionally, 84% of the subjects were able to distinguish the cricket bar from the market alternative. This suggests that products developed using cricket protein powder will need to modify the sensory attributes accordingly to successfully integrate edible insects in the diet of the western society.
Subjects/Keywords: Food science
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APA (6th Edition):
Zhong, A. (2017). Product Development Considerations for a Nutrient Rich Bar Using Cricket (Acheta domesticus) Protein. (Thesis). California State University, Long Beach. Retrieved from http://pqdtopen.proquest.com/#viewpdf?dispub=10262776
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Zhong, Amy. “Product Development Considerations for a Nutrient Rich Bar Using Cricket (Acheta domesticus) Protein.” 2017. Thesis, California State University, Long Beach. Accessed February 28, 2021.
http://pqdtopen.proquest.com/#viewpdf?dispub=10262776.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Zhong, Amy. “Product Development Considerations for a Nutrient Rich Bar Using Cricket (Acheta domesticus) Protein.” 2017. Web. 28 Feb 2021.
Vancouver:
Zhong A. Product Development Considerations for a Nutrient Rich Bar Using Cricket (Acheta domesticus) Protein. [Internet] [Thesis]. California State University, Long Beach; 2017. [cited 2021 Feb 28].
Available from: http://pqdtopen.proquest.com/#viewpdf?dispub=10262776.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Zhong A. Product Development Considerations for a Nutrient Rich Bar Using Cricket (Acheta domesticus) Protein. [Thesis]. California State University, Long Beach; 2017. Available from: http://pqdtopen.proquest.com/#viewpdf?dispub=10262776
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Minnesota
12.
Tremaine, Andrea Jane.
Twin-screw extrusion of commodity grade dairy ingredients
to ingredients to produce value-added products.
Degree: MS, Food science, 2012, University of Minnesota
URL: http://purl.umn.edu/131156
University of Minnesota M.S. thesis. May 2012.
Major: Food science. Advisor: Tonya Schoenfuss, Ph.D. 1 computer
file (PDF); v, 144 pages, appendix p. 98-144.
Abstract summary not available
Advisors/Committee Members: Tonya Schoenfuss, Ph.D.Subjects/Keywords: Food Science
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APA ·
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Manager
APA (6th Edition):
Tremaine, A. J. (2012). Twin-screw extrusion of commodity grade dairy ingredients
to ingredients to produce value-added products. (Masters Thesis). University of Minnesota. Retrieved from http://purl.umn.edu/131156
Chicago Manual of Style (16th Edition):
Tremaine, Andrea Jane. “Twin-screw extrusion of commodity grade dairy ingredients
to ingredients to produce value-added products.” 2012. Masters Thesis, University of Minnesota. Accessed February 28, 2021.
http://purl.umn.edu/131156.
MLA Handbook (7th Edition):
Tremaine, Andrea Jane. “Twin-screw extrusion of commodity grade dairy ingredients
to ingredients to produce value-added products.” 2012. Web. 28 Feb 2021.
Vancouver:
Tremaine AJ. Twin-screw extrusion of commodity grade dairy ingredients
to ingredients to produce value-added products. [Internet] [Masters thesis]. University of Minnesota; 2012. [cited 2021 Feb 28].
Available from: http://purl.umn.edu/131156.
Council of Science Editors:
Tremaine AJ. Twin-screw extrusion of commodity grade dairy ingredients
to ingredients to produce value-added products. [Masters Thesis]. University of Minnesota; 2012. Available from: http://purl.umn.edu/131156
University of Minnesota
13.
Opoku, Abena Opokua Bampo.
Alternative Processing Methods for the Inactivation of
Escherichia coli O157:H7, Salmonella and Listeria monocytogenes in
skim milk.
Degree: MS, Food science, 2012, University of Minnesota
URL: http://purl.umn.edu/140644
University of Minnesota M.S. thesis. July 2012.
Major: Food science. Advisor: Dr. Francisco Diez-González. 1
computer file (PDF); viii, 115 pages, appendix p.
86-115.
Abstract summary not available
Advisors/Committee Members: Dr. Francisco Diez-González.Subjects/Keywords: Food science
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APA (6th Edition):
Opoku, A. O. B. (2012). Alternative Processing Methods for the Inactivation of
Escherichia coli O157:H7, Salmonella and Listeria monocytogenes in
skim milk. (Masters Thesis). University of Minnesota. Retrieved from http://purl.umn.edu/140644
Chicago Manual of Style (16th Edition):
Opoku, Abena Opokua Bampo. “Alternative Processing Methods for the Inactivation of
Escherichia coli O157:H7, Salmonella and Listeria monocytogenes in
skim milk.” 2012. Masters Thesis, University of Minnesota. Accessed February 28, 2021.
http://purl.umn.edu/140644.
MLA Handbook (7th Edition):
Opoku, Abena Opokua Bampo. “Alternative Processing Methods for the Inactivation of
Escherichia coli O157:H7, Salmonella and Listeria monocytogenes in
skim milk.” 2012. Web. 28 Feb 2021.
Vancouver:
Opoku AOB. Alternative Processing Methods for the Inactivation of
Escherichia coli O157:H7, Salmonella and Listeria monocytogenes in
skim milk. [Internet] [Masters thesis]. University of Minnesota; 2012. [cited 2021 Feb 28].
Available from: http://purl.umn.edu/140644.
Council of Science Editors:
Opoku AOB. Alternative Processing Methods for the Inactivation of
Escherichia coli O157:H7, Salmonella and Listeria monocytogenes in
skim milk. [Masters Thesis]. University of Minnesota; 2012. Available from: http://purl.umn.edu/140644
University of Minnesota
14.
Vaidyanathan, Sharmila.
Development and application of a methodology to determine
different ferulic acid populations in cereals and cereal based
products.
Degree: MS, Food Science, 2012, University of Minnesota
URL: http://purl.umn.edu/140689
University of Minnesota M.S. thesis. January 2012.
Major: Food Science. Advisor: Dr.Mirko Bunzel. 1 computer file
(PDF); ix, 105 pages, appendices A-E.
Abstract summary not available
Advisors/Committee Members: Dr.Mirko Bunzel.Subjects/Keywords: Food Science
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APA ·
Chicago ·
MLA ·
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Manager
APA (6th Edition):
Vaidyanathan, S. (2012). Development and application of a methodology to determine
different ferulic acid populations in cereals and cereal based
products. (Masters Thesis). University of Minnesota. Retrieved from http://purl.umn.edu/140689
Chicago Manual of Style (16th Edition):
Vaidyanathan, Sharmila. “Development and application of a methodology to determine
different ferulic acid populations in cereals and cereal based
products.” 2012. Masters Thesis, University of Minnesota. Accessed February 28, 2021.
http://purl.umn.edu/140689.
MLA Handbook (7th Edition):
Vaidyanathan, Sharmila. “Development and application of a methodology to determine
different ferulic acid populations in cereals and cereal based
products.” 2012. Web. 28 Feb 2021.
Vancouver:
Vaidyanathan S. Development and application of a methodology to determine
different ferulic acid populations in cereals and cereal based
products. [Internet] [Masters thesis]. University of Minnesota; 2012. [cited 2021 Feb 28].
Available from: http://purl.umn.edu/140689.
Council of Science Editors:
Vaidyanathan S. Development and application of a methodology to determine
different ferulic acid populations in cereals and cereal based
products. [Masters Thesis]. University of Minnesota; 2012. Available from: http://purl.umn.edu/140689
University of Minnesota
15.
Gray, Dorey Lynn.
Survival and germination potential of spore forming
bacteria in cheese sauce.
Degree: MS, Food science, 2012, University of Minnesota
URL: http://purl.umn.edu/140766
► University of Minnesota M.S. thesis. August 2012. Major: Food science. Advisor: Dr. Francisco Diez-Gonzalez. 1 computer file (PDF); viii, 102 pages.
Process cheese sauce is…
(more)
▼ University of Minnesota M.S. thesis. August 2012.
Major: Food science. Advisor: Dr. Francisco Diez-Gonzalez. 1
computer file (PDF); viii, 102 pages.
Process cheese sauce is typically prepared by
combining one or more natural cheeses of the same type or different
varieties, mixing with emulsifying salts and other dairy
ingredients, and thermal processing to temperatures above 90°C. The
processing renders the product free of all viable organisms and is
considered commercially sterile. Despite the safety of process
cheese sauce during processing, its low acid and high moisture
environment are conducive to support the growth of bacteria
contaminated by the consumer. Spore-forming bacteria such as
Bacillus cereus and Clostridium perfringens are particularly
problematic because their spores state can survive temperatures
above the required reheating temperature of 60°C and the sub-lethal
heating could induce germination in the cheese sauce medium if the
product is mishandled. The goal of this project was to assess the
survival and germination potential of sporeforming bacteria in
process cheese sauce through typical temperature-abuse schemes that
could happen in a food service setting. Commercial cheese sauce was
inoculated with cocktails of B. cereus and C. perfringens at 104
CFU/g and held at temperatures of 4, 12, 23, 37, and 45°C for
short-term and long-term storage. Cyclic temperature scenarios
typical of commercial buffet restaurants were also evaluated, as
well as the use of a common antimicrobial nisin for B. cereus.
Three strains of each bacterium were combined and tested in each
sample and bacterial counts were determined by direct plating on
PEMB agar for B. cereus and anaerobic blood agar for C.
perfringens. Bacillus cereus germinated well in the cheese sauce
medium. At 37°C the vegetative cell population reached 8 log CFU/g
after 24 hours, but took 48 hours to reach the same level when the
antimicrobial nisin was added. At temperatures of 23°C and 45°C,
vegetative cell populations reached 8 log CFU/g within 48 hours and
at 12°C reached 7 log CFU/g after 1 month. When incubated at 4°C no
growth was observed even after 2 months. Almost no increase in B.
cereus spore count was observed at any temperature, except at 23°C.
The B. cereus inoculated cheese sauce was subjected to cyclic
temperature abuse schemes that simulated a buffet restaurant
schedule. One scenario depicted samples that were not properly
heated (below 60°C) on the buffet line. Short incubation times at
abusive temperatures did not influence germination, but after 24
hours of fluctuating temperatures vegetative cells began to grow.
However, when the contaminated sample was reheated to temperatures
above 60°C vegetative cells actually began to decrease. The cheese
sauce matrix did not support germination and growth of C.
perfringens at any temperature. Even during a worst case scenario
where the cheese sauce was allowed to cool from 75°C to 4°C in a 9
hour period, vegetative cell and spore counts declined below a
detectable level. In almost all…
Advisors/Committee Members: Dr. Francisco Diez-Gonzalez.
Subjects/Keywords: Food science
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APA ·
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Manager
APA (6th Edition):
Gray, D. L. (2012). Survival and germination potential of spore forming
bacteria in cheese sauce. (Masters Thesis). University of Minnesota. Retrieved from http://purl.umn.edu/140766
Chicago Manual of Style (16th Edition):
Gray, Dorey Lynn. “Survival and germination potential of spore forming
bacteria in cheese sauce.” 2012. Masters Thesis, University of Minnesota. Accessed February 28, 2021.
http://purl.umn.edu/140766.
MLA Handbook (7th Edition):
Gray, Dorey Lynn. “Survival and germination potential of spore forming
bacteria in cheese sauce.” 2012. Web. 28 Feb 2021.
Vancouver:
Gray DL. Survival and germination potential of spore forming
bacteria in cheese sauce. [Internet] [Masters thesis]. University of Minnesota; 2012. [cited 2021 Feb 28].
Available from: http://purl.umn.edu/140766.
Council of Science Editors:
Gray DL. Survival and germination potential of spore forming
bacteria in cheese sauce. [Masters Thesis]. University of Minnesota; 2012. Available from: http://purl.umn.edu/140766
University of Minnesota
16.
Folly, Edem-Elikplim E.
Enhancing the functionality of delactosed whey by
enzymatic hydrolysis using Response Surface Methodology Approach
(RSM).
Degree: MS, Food Science, 2012, University of Minnesota
URL: http://purl.umn.edu/140889
► University of Minnesota M.S. thesis. September 2012. Major: Food Science. Advisor: Baraem Ismail. 1 computer file (PDF); xiii, 107 pages, appendices A-G.
Delactosed whey (DLW),…
(more)
▼ University of Minnesota M.S. thesis. September
2012. Major: Food Science. Advisor: Baraem Ismail. 1 computer file
(PDF); xiii, 107 pages, appendices A-G.
Delactosed whey (DLW), which has ~24% protein, is a
by-product of lactose production and is mostly used as animal feed.
DLW applications can be expanded to include food products, and its
economic value improved by amplifying its protein functionality.
Moderate enzymatic hydrolysis can significantly enhance protein
functionality. It is, therefore, hypothesized that subjecting DLW
to enzymatic proteolysis will lead to enhanced functionality. To
amplify and improve the functionality of DLW via enzymatic
hydrolysis, hydrolysis conditions need to be optimized. The
infinite number of possible combinations of factors and their
levels to be tested makes the task quite challenging. Using
response surface methodology (RSM), the number of experimental
units necessary to find the optimal point can be tailored depending
on the time and resource constraints of the experimenter. The first
objective was, therefore, to amplify the functional properties of
the protein component of DLW by enzymatic hydrolysis using response
surface methodology (RSM). The second objective was to monitor the
functional properties and sensory quality of beef patties fortified
with selected DLW hydrolysates as compared to those fortified with
whey protein isolate (WPI) and whey protein concentrate 34% (WPC
34). In order to determine the optimal hydrolysis conditions, a
Box-Behnken design with 4 independent variables at 3 levels was
generated and implemented. The variables chosen, temperature (x1),
enzyme-to-substrate (e/s) ratio (x2), time (x3) and pH (x4), are
known to have the most significant influence on the degree of
hydrolysis (DH) and protein functionality. The design had 27
experimental units that included 3 center points to assess the pure
error. Each experimental unit was run in triplicate and the means
of DH and measured functional properties were recorded as the y
responses. The behavior of each response was explained by a
quadratic equation. The effect of the independent variables on each
response was evaluated and tridimensional response plots were
generated. The conditions at which the responses were
maximal/optimal were then determined. To validate the model,
experimental data was obtained using the predicted optimized
levels. iii In triplicate, ground beef patties were formulated
using selected DLW hydrolysates, with optimized functionality,
non-hydrolyzed DLW, WPC34 or WPI. A control sample was formulated
without the addition of any whey protein ingredient. Cook loss due
to losses in water and fat was assessed. Texture analysis of the
cooked patties was done using a TA-XT2 texture analyzer. Sensory
analysis was conducted to determine differences in various
attributes among the different beef patties. Several response
surface models were compared to determine the best fit for the RSM
data collected. The point within the range of experimentation with
the highest fitted value was…
Advisors/Committee Members: Baraem Ismail.
Subjects/Keywords: Food science
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APA (6th Edition):
Folly, E. E. (2012). Enhancing the functionality of delactosed whey by
enzymatic hydrolysis using Response Surface Methodology Approach
(RSM). (Masters Thesis). University of Minnesota. Retrieved from http://purl.umn.edu/140889
Chicago Manual of Style (16th Edition):
Folly, Edem-Elikplim E. “Enhancing the functionality of delactosed whey by
enzymatic hydrolysis using Response Surface Methodology Approach
(RSM).” 2012. Masters Thesis, University of Minnesota. Accessed February 28, 2021.
http://purl.umn.edu/140889.
MLA Handbook (7th Edition):
Folly, Edem-Elikplim E. “Enhancing the functionality of delactosed whey by
enzymatic hydrolysis using Response Surface Methodology Approach
(RSM).” 2012. Web. 28 Feb 2021.
Vancouver:
Folly EE. Enhancing the functionality of delactosed whey by
enzymatic hydrolysis using Response Surface Methodology Approach
(RSM). [Internet] [Masters thesis]. University of Minnesota; 2012. [cited 2021 Feb 28].
Available from: http://purl.umn.edu/140889.
Council of Science Editors:
Folly EE. Enhancing the functionality of delactosed whey by
enzymatic hydrolysis using Response Surface Methodology Approach
(RSM). [Masters Thesis]. University of Minnesota; 2012. Available from: http://purl.umn.edu/140889
University of Minnesota
17.
Peck, Amanda.
The effects of swallowing and expectorating on basic
taste perception, flavor perception, and concentration of volatile
compound in the nasal headspace.
Degree: 2012, University of Minnesota
URL: http://purl.umn.edu/140922
University of Minnesota M.S. thesis. September
2012. Major: Food science. Advisor:Zata Vickers, Ph.D. 1 computer
file (PDF); v, 97 pages, appendices A-G.
Subjects/Keywords: Food science
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APA (6th Edition):
Peck, A. (2012). The effects of swallowing and expectorating on basic
taste perception, flavor perception, and concentration of volatile
compound in the nasal headspace. (Masters Thesis). University of Minnesota. Retrieved from http://purl.umn.edu/140922
Chicago Manual of Style (16th Edition):
Peck, Amanda. “The effects of swallowing and expectorating on basic
taste perception, flavor perception, and concentration of volatile
compound in the nasal headspace.” 2012. Masters Thesis, University of Minnesota. Accessed February 28, 2021.
http://purl.umn.edu/140922.
MLA Handbook (7th Edition):
Peck, Amanda. “The effects of swallowing and expectorating on basic
taste perception, flavor perception, and concentration of volatile
compound in the nasal headspace.” 2012. Web. 28 Feb 2021.
Vancouver:
Peck A. The effects of swallowing and expectorating on basic
taste perception, flavor perception, and concentration of volatile
compound in the nasal headspace. [Internet] [Masters thesis]. University of Minnesota; 2012. [cited 2021 Feb 28].
Available from: http://purl.umn.edu/140922.
Council of Science Editors:
Peck A. The effects of swallowing and expectorating on basic
taste perception, flavor perception, and concentration of volatile
compound in the nasal headspace. [Masters Thesis]. University of Minnesota; 2012. Available from: http://purl.umn.edu/140922
University of Minnesota
18.
Hohn, Allison Carlquist.
Enzyme treatment of wheat bran to release antioxidants
and combination processing to further enhance this
release.
Degree: MS, Food science, 2012, University of Minnesota
URL: http://purl.umn.edu/143824
► University of Minnesota M.S. thesis. December 2012. Major: Food science. Advisor: Roger Ruan. 1 computer file (PDF); viii, 89 pages, appendices A-C.
Whole grains have…
(more)
▼ University of Minnesota M.S. thesis. December 2012.
Major: Food science. Advisor: Roger Ruan. 1 computer file (PDF);
viii, 89 pages, appendices A-C.
Whole grains have long been associated with good
health due to the complex carbohydrates, vitamins, and other
nutrients such as antioxidants, found within them. It is this last
class that has the most untapped nutritional power when looking at
whole grain products. This is because a majority of the
antioxidants found are in the insoluble bound form and are not
bioavailable to the consumer. Treating whole grains with multiple
processes, including physical, chemical, and biological, can
release some of these nutrients into a free or soluble bound form
that is much more bioavailable, making the whole grain products
much more beneficial to health. Treating wheat bran with different
individual and combinations of enzymes over varying lengths of time
and at different concentrations was done in a 3x4 factorial to show
which combination led to the highest release of the indicator
phenolic compound- ferulic acid. The information from enzyme
optimization was then combined with multiple pre-processing steps
including a NaOH soaking period, high shear mixing, and high
pressure homogenization to provide the greatest increase in ferulic
acid release, as well as the largest increase in viscosity, which
is a positive driver for functionality in whole grain products.
Results of the enzyme optimization study showed the highest release
was almost always found at the highest concentration and time
combination- 1.0% and 48 hours. Three individual enzymes showed
high release- Xylanase BX-AN, S and Pentopan. The testing done on
combinations of enzymes did not show a significantly larger release
than any individual enzyme and so a synergistic effect among
enzymes was not found. When testing the enzyme with the
pre-processing steps there was a significant increase in the
release of ferulic acid. The NaOH soaking treatment proved
extremely effective in aiding in release of ferulic acid. The high
pressure homogenization treatment provided a dramatic increase in
viscosity. Overall, the combination of treatments gave the highest
release of ferulic acid and the largest increase in viscosity. A
preliminary animal study was done that showed the use of treated
wheat bran gave an increase in intestinal contents viscosity, which
leads to cholesterol lowering. A longer 12 week study by another
graduate student is planned to confirm these
findings.
Advisors/Committee Members: Roger Ruan.
Subjects/Keywords: Food science
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APA ·
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MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Hohn, A. C. (2012). Enzyme treatment of wheat bran to release antioxidants
and combination processing to further enhance this
release. (Masters Thesis). University of Minnesota. Retrieved from http://purl.umn.edu/143824
Chicago Manual of Style (16th Edition):
Hohn, Allison Carlquist. “Enzyme treatment of wheat bran to release antioxidants
and combination processing to further enhance this
release.” 2012. Masters Thesis, University of Minnesota. Accessed February 28, 2021.
http://purl.umn.edu/143824.
MLA Handbook (7th Edition):
Hohn, Allison Carlquist. “Enzyme treatment of wheat bran to release antioxidants
and combination processing to further enhance this
release.” 2012. Web. 28 Feb 2021.
Vancouver:
Hohn AC. Enzyme treatment of wheat bran to release antioxidants
and combination processing to further enhance this
release. [Internet] [Masters thesis]. University of Minnesota; 2012. [cited 2021 Feb 28].
Available from: http://purl.umn.edu/143824.
Council of Science Editors:
Hohn AC. Enzyme treatment of wheat bran to release antioxidants
and combination processing to further enhance this
release. [Masters Thesis]. University of Minnesota; 2012. Available from: http://purl.umn.edu/143824
University of Minnesota
19.
Gadotti, Camila.
Control of pathogenic bacteria in Queso Fresco by using
generally recognized as safe ingredients.
Degree: MS, Food science, 2011, University of Minnesota
URL: http://purl.umn.edu/113938
► University of Minnesota M.S. thesis. July 2011. Major: Food science. Advisor: Dr. Francisco Diez-Gonzalez. 1 computer file (PDF); xii, 115 pages.
Soft-style fresh Hispanic cheeses…
(more)
▼ University of Minnesota M.S. thesis. July 2011.
Major: Food science. Advisor: Dr. Francisco Diez-Gonzalez. 1
computer file (PDF); xii, 115 pages.
Soft-style fresh Hispanic cheeses like “queso
fresco” are generally prepared through minimal processing and
recent outbreaks have shown that they can be a vehicle of
transmission of L. monocytogenes, Salmonella, and E. coli O157:H7.
Currently there are no available treatments to reduce
post-pasteurization contamination. The goal of this research was to
identify effective queso fresco antimicrobial treatments using
available Generally Recognized as Safe (GRAS) ingredients. These
antimicrobial agents included nisin (Nisaplin®), caprylic acid,
trans-cinnamaldehyde, monolaurin, carvacrol, eugenol, levulinic
acid, orange-terpenes, d-limonene, eucalyptol, thymol, and clove
essential oils. Batches of queso fresco were inoculated with
mixtures of approximately 104 CFU/g of different L. monocytogenes,
Salmonella, or E. coli O157:H7 strains/serovars and treated with
different combinations of antimicrobials. Twenty five strains of L.
monocytogenes, 28 strains of S. enterica, and 24 strains of E. coli
O157:H7 were tested. Inoculated queso fresco samples were stored at
4˚C or 8˚C for 3 weeks and the bacterial count was determined every
other day by direct plating onto PALCAM, bismuth sulfate, or
sorbitol MacConkey agar. All nisin and caprylic acid combinations
were effective to decrease survival and growth of all L.
monocytogenes and caused at least 4 log CFU/g reductions by the end
of storage compared to controls. The levels of most strain mixtures
were markedly reduced immediately after treatment and their numbers
remained below 103 CFU/ g during the experiments. Combinations of
nisin and caprylic acid were only effective to reduce at least 2
log CFU/g Salmonella and E. coli O157:H7 if the caprylic acid
concentration was greater than 2 g/kg and 0.7 g/kg respectively.
Treatments that included cinnamaldehyde (1 to 2 g/kg) reduced
Salmonella and E. coli O157:H7 counts almost 3 and 5 log CFU/g
respectively. The combination of nisin, caprylic acid, and
cinnamaldehyde was the only antimicrobial treatment able to
noticeably inhibit the growth of L. monocytogenes, Salmonella, and
E. coli O157:H7 in queso fresco. This combination was also tested
to evaluate the impact on the quality and sensory attributes of the
cheese. For the quality and sensory analysis, treated cheese
samples (sample A containing 0.5 g/kg nisin, 0.4 g/kg caprylic
acid, and 0.3 g/kg cinnamaldehyde, sample B containing 0.5 g/kg
nisin, 0.4 g/kg caprylic acid, and 0.6 g/kg cinnamaldehyde) were
stored over a four week period and tested for lactic acid bacteria,
aerobic plate count, and psychrotrophic plate counts. Treated queso
fresco samples stored for 4 weeks had similar numbers of lactic
acid bacteria, aerobic plate counts, and psychrotrophic plate
counts to those of control samples. These results indicated that
the treatments had no effect on the growth of potential background
spoilage microorganisms. A consumer liking…
Advisors/Committee Members: Dr. Francisco Diez-Gonzalez.
Subjects/Keywords: Food science
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APA (6th Edition):
Gadotti, C. (2011). Control of pathogenic bacteria in Queso Fresco by using
generally recognized as safe ingredients. (Masters Thesis). University of Minnesota. Retrieved from http://purl.umn.edu/113938
Chicago Manual of Style (16th Edition):
Gadotti, Camila. “Control of pathogenic bacteria in Queso Fresco by using
generally recognized as safe ingredients.” 2011. Masters Thesis, University of Minnesota. Accessed February 28, 2021.
http://purl.umn.edu/113938.
MLA Handbook (7th Edition):
Gadotti, Camila. “Control of pathogenic bacteria in Queso Fresco by using
generally recognized as safe ingredients.” 2011. Web. 28 Feb 2021.
Vancouver:
Gadotti C. Control of pathogenic bacteria in Queso Fresco by using
generally recognized as safe ingredients. [Internet] [Masters thesis]. University of Minnesota; 2011. [cited 2021 Feb 28].
Available from: http://purl.umn.edu/113938.
Council of Science Editors:
Gadotti C. Control of pathogenic bacteria in Queso Fresco by using
generally recognized as safe ingredients. [Masters Thesis]. University of Minnesota; 2011. Available from: http://purl.umn.edu/113938
University of Minnesota
20.
Chick, Matt.
Thermal inactivation kinetics of Salmonella serovars on
dry cereal.
Degree: MS, Food science, 2011, University of Minnesota
URL: http://purl.umn.edu/116854
► University of Minnesota M.S. thesis. August 2011. Major: Food science. Advisor: Dr. Francisco Diez-Gonzalez. 1 computer file (PDF); ix, 93 pages, appendices A-B.
Outbreaks of…
(more)
▼ University of Minnesota M.S. thesis. August 2011.
Major: Food science. Advisor: Dr. Francisco Diez-Gonzalez. 1
computer file (PDF); ix, 93 pages, appendices A-B.
Outbreaks of Salmonella linked to low water
activity foods have been an increasing concern to the food
industry, as Salmonella is the leading causative agent of bacterial
foodborne illness in the United States. Some of the most recent
foods linked to outbreaks include low water activity foods, such as
peanut butter, dry cereal, and black pepper. Several studies have
indicated that the thermal resistance of Salmonella at low water
activity increases significantly, but very few kinetic studies have
been published. The goal of this reaserch was to determine the
kenetic parameters of thermal resistance of Salmonella in a low
water activity food. Cereal with water activity levels between 0.1
and 0.5 (aw) was used as the model food. and the effect of sucrose
addition was also assessed. The model toasted oat cereal was
inoculated with 10(8) CFU/mL of one of three Salmonella serovars,
dried overnight at 40 degrees centrigrade and equilibrated to 0.11,
0.33 or 0.53 water activity. The cereal was then ground, put into
sealed capillary tubes and heated at temperatures between 65 and
105 degrees centrigrade. The capillary tubes were removed at
intervals, immediately cooled and then plated onto
Salmonella-specific differential tryptic soy agar. The inactivation
curves were the plotted and lines of best fit used were used to
calculate D and Z-values for each serovar at a given temperature
and water activity. Sucrose (25%) was also added to the cereal to
assess its effect on thermal resistance. Using Salmonella serovars
Typhimurium, Tennessee and Agona, at 0.53 water activity, the
D-values ranged from 172 to 208 min at 65 degrees centrigrade and
from 4.3 to 6.5 min 80 degrees centrigrade among the three
serovars. D-values at 80 degrees centrigrade increased 4-fold when
the water activity was reduced to 0.33. All serovars became more
resistant to thermal treatments as the water activity decreased,
and at 0.11 (aw) D-values greater than 135 min were measured at 85
degrees centrigrade. At 0.53(aw) the D-values of each of the three
serovars increased between 32 and 102% at 80 degreees centrigrade
once sucrose was added to the cereal. At 0.33 (aw) the
serovars'D-values increased by 95 to 152% at 85 degrees centrigrade
compared to the cereal without sucrose. Once the water activity was
lowered to 0.11, each of the three serovars had a decrease in
D-values of between 46 and 85% at every temperature tested. The
Z-values for the three serovars at 0.33 and 0.53 (aw) were
approximately 10 degrees centrigrade, but this value increased from
20 to 50% if the serovars were tested at 0.11 (aw). there was not a
statistically significant change in the Z-values due to the
addition of sucrose. The thermal resistance of Salmonella increased
dramatically at very low water activity. This increase may render
some food processes, once thought to be able to control Salmonella,
ineffective at…
Advisors/Committee Members: Dr. Francisco Diez-Gonzalez.
Subjects/Keywords: Food science
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Manager
APA (6th Edition):
Chick, M. (2011). Thermal inactivation kinetics of Salmonella serovars on
dry cereal. (Masters Thesis). University of Minnesota. Retrieved from http://purl.umn.edu/116854
Chicago Manual of Style (16th Edition):
Chick, Matt. “Thermal inactivation kinetics of Salmonella serovars on
dry cereal.” 2011. Masters Thesis, University of Minnesota. Accessed February 28, 2021.
http://purl.umn.edu/116854.
MLA Handbook (7th Edition):
Chick, Matt. “Thermal inactivation kinetics of Salmonella serovars on
dry cereal.” 2011. Web. 28 Feb 2021.
Vancouver:
Chick M. Thermal inactivation kinetics of Salmonella serovars on
dry cereal. [Internet] [Masters thesis]. University of Minnesota; 2011. [cited 2021 Feb 28].
Available from: http://purl.umn.edu/116854.
Council of Science Editors:
Chick M. Thermal inactivation kinetics of Salmonella serovars on
dry cereal. [Masters Thesis]. University of Minnesota; 2011. Available from: http://purl.umn.edu/116854
University of Minnesota
21.
DeClark, Brian James.
Thiamine degradation off-flavors in energy beverages and
their reduction.
Degree: MS, Food science, 2011, University of Minnesota
URL: http://purl.umn.edu/116936
University of Minnesota M.S. thesis. September
2011. Major: Food science. Advisor: Dr. Gary Reineccius. 1 computer
file (PDF); vii, 50 pages.
Abstract summary not available
Advisors/Committee Members: Dr. Gary Reineccius.Subjects/Keywords: Food science
Record Details
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
DeClark, B. J. (2011). Thiamine degradation off-flavors in energy beverages and
their reduction. (Masters Thesis). University of Minnesota. Retrieved from http://purl.umn.edu/116936
Chicago Manual of Style (16th Edition):
DeClark, Brian James. “Thiamine degradation off-flavors in energy beverages and
their reduction.” 2011. Masters Thesis, University of Minnesota. Accessed February 28, 2021.
http://purl.umn.edu/116936.
MLA Handbook (7th Edition):
DeClark, Brian James. “Thiamine degradation off-flavors in energy beverages and
their reduction.” 2011. Web. 28 Feb 2021.
Vancouver:
DeClark BJ. Thiamine degradation off-flavors in energy beverages and
their reduction. [Internet] [Masters thesis]. University of Minnesota; 2011. [cited 2021 Feb 28].
Available from: http://purl.umn.edu/116936.
Council of Science Editors:
DeClark BJ. Thiamine degradation off-flavors in energy beverages and
their reduction. [Masters Thesis]. University of Minnesota; 2011. Available from: http://purl.umn.edu/116936
University of Minnesota
22.
Lee, Jookyeong.
Soy protein hydrolysate; solubility, thermal stability,
bioactivity, and sensory acceptability in a tea
beverage.
Degree: MS, Food science, 2011, University of Minnesota
URL: http://purl.umn.edu/117047
► University of Minnesota M.S. thesis. August 2011. Major: Food science. Advisors: Baraem Ismail and Zata M.Vickers. 1 computer file (PDF); xiii, 117 pages, appendices A-L.…
(more)
▼ University of Minnesota M.S. thesis. August 2011.
Major: Food science. Advisors: Baraem Ismail and Zata M.Vickers. 1
computer file (PDF); xiii, 117 pages, appendices
A-L.
Protein solubility affects the quality of many food
products, especially high-protein beverages (>4.2% protein).
Beverages formulated with soy protein at >4.2% protein content
are currently unavailable in the market due to thermal challenges
affecting the protein solubility and also due to flavor challenges.
Enzyme hydrolysis of soy protein may lead to enhanced solubility
and thermal stability. However, bitter taste caused by hydrolyzing
soy protein is a limiting factor to using SPH in food applications.
Therefore, controlled and limited hydrolysis of 2-8% is required to
minimize the production of bitter peptides. Another advantage of
controlled hydrolysis of soy protein is the release of bioactive
peptides. Among the many physiological benefits of bioactive
peptides, antihypertensive activity has gained much attention.
Therefore the objectives of this work were 1) to optimize
hydrolysis conditions of soy protein for enhanced solubility,
thermal stability and bioactivity, while maintaining low degree of
hydrolysis (DH); and 2) to determine the sensory acceptability of
lemon flavored iced tea beverages formulated with soy protein
hydrolysate at various concentrations. Soy protein isolate (SPI)
was hydrolyzed by papain, bromelain, trypsin, and alcalase at
various enzyme levels while keeping other hydrolysis conditions
constant. Enzymatic activities were optimized based on DH
measurements. Degree of hydrolysis (DH) was measured using
O-phthaldialdehyde method. Samples were subjected to SDS-PAGE
analysis to monitor enzyme selectivity. ACE inhibitory activity was
measured using a standardized assay. For determination of
solubility and thermal stability, solutions (5% w/v) of
hydrolysates and SPI were subjected to heat treatment at 95°C for
60 min followed by centrifugation and determination of protein
content in the supernatant using a nitrogen analyzer. Solubility
and thermal stability at different protein concentrations (1%,
2.5%, 5%, and 7%) in a black tea beverage were also measured.
Alcalase-hydrolyzed SPI was chosen for the sensory study as it had
the highest solubility, thermal stability, and antihypertensive
activity among the hydrolysates. Nine formulations were prepared,
including a control which was a tea with no added protein and the
four different protein concentrations containing either SPI or
alcalase-hydrolyzed SPI. One-hundred-one subjects rated overall
liking, flavor, aroma, appearance, and mouthfeel on an 11-point
hedonic scale and rated intensity of bitterness and off flavor on a
line scale. Hydrolysates produced using 2.654 GDU of bromelain,
0.012 AU-A of alcalase, 19,680 USP units of papain, and 235,000 U
of trypsin had DH of 3.98%, 3.57%, 6.77%, and 2.60%, respectively,
thus were selected for further experiments. Use of different
enzymes resulted in distinctive differences in hydrolysis patterns.
Among the four produced…
Advisors/Committee Members: Baraem Ismail and Zata M.Vickers.
Subjects/Keywords: Food science
Record Details
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lee, J. (2011). Soy protein hydrolysate; solubility, thermal stability,
bioactivity, and sensory acceptability in a tea
beverage. (Masters Thesis). University of Minnesota. Retrieved from http://purl.umn.edu/117047
Chicago Manual of Style (16th Edition):
Lee, Jookyeong. “Soy protein hydrolysate; solubility, thermal stability,
bioactivity, and sensory acceptability in a tea
beverage.” 2011. Masters Thesis, University of Minnesota. Accessed February 28, 2021.
http://purl.umn.edu/117047.
MLA Handbook (7th Edition):
Lee, Jookyeong. “Soy protein hydrolysate; solubility, thermal stability,
bioactivity, and sensory acceptability in a tea
beverage.” 2011. Web. 28 Feb 2021.
Vancouver:
Lee J. Soy protein hydrolysate; solubility, thermal stability,
bioactivity, and sensory acceptability in a tea
beverage. [Internet] [Masters thesis]. University of Minnesota; 2011. [cited 2021 Feb 28].
Available from: http://purl.umn.edu/117047.
Council of Science Editors:
Lee J. Soy protein hydrolysate; solubility, thermal stability,
bioactivity, and sensory acceptability in a tea
beverage. [Masters Thesis]. University of Minnesota; 2011. Available from: http://purl.umn.edu/117047
University of Minnesota
23.
Guo, Mufan.
Effects of chemical, enzymatic and mechanical treatments
on the phenolics and water holding capacity in wheat
bran.
Degree: 2011, University of Minnesota
URL: http://purl.umn.edu/120086
► University of Minnesota M.S. thesis. December 2011. Major: Food science.. Advisor: Roger Ruan. 1 computer file (PDF); viii, 132 pages, appendix p. 115-132.
Epidemiological studies…
(more)
▼ University of Minnesota M.S. thesis. December 2011.
Major: Food science.. Advisor: Roger Ruan. 1 computer file (PDF);
viii, 132 pages, appendix p. 115-132.
Epidemiological studies have demonstrated that
consumption of whole grain products is beneficial for human health
due to its high dietary fiber content, and the consumption of
fruits and vegetables can prevent chronic disease due to their high
antioxidant activity. However, whole grain is also a good source of
antioxidant, which has been underestimated by literature because
most antioxidants in grains exist in their bound form, which cannot
be detected using previous analysis methods. With the development
of new approach to analyze the bound phenolics, scientists find the
bound phenolics can take up almost as high as 70-80% of the total
phenolics. Wheat bran is a good source of dietary fiber and also
phenolics. The phenolics in wheat bran are mainly ferulic acid,
which is bound to arabinose, the side chain of arabinoxylans,
through ester linkage. The bound phenolics reduce the bioactivity
and bioaccesibility of wheat bran. Therefore, releasing them from
the complex polysaccharides structure is beneficial for the
functionality and bioactivity of wheat bran. This objective of this
study is to optimize the conditions to improve the bioavailability
of free phenolics from wheat bran using combined physical,
chemical, thermal, and enzymatic treatments. The treatments include
alkaline treatment, enzymatic treatment, high shear mixing, and
high-pressure homogenization. In this study, the optimal conditions
of enzymatic treatment and combined alkaline and enzymatic
treatments were evaluated. The phenolics acids content, flavonoids
content, ferulic acid content and the water holding capacity were
determined in processed wheat bran. Results showed that alkaline
treatment was the most efficient in releasing bound phenolics in
wheat bran due to its strong hydrolysis capacity of cleaving the
ester linkage. Enzymatic treatment was the most efficient in
releasing flavonoids in wheat bran due to its effects on opening
the polysaccharide structure. Mechanical treatments helped to
reduce the particle size and opened the polysaccharide structure
and improve the functionality and bioactivity of wheat bran as
well.
Subjects/Keywords: Food science
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APA (6th Edition):
Guo, M. (2011). Effects of chemical, enzymatic and mechanical treatments
on the phenolics and water holding capacity in wheat
bran. (Masters Thesis). University of Minnesota. Retrieved from http://purl.umn.edu/120086
Chicago Manual of Style (16th Edition):
Guo, Mufan. “Effects of chemical, enzymatic and mechanical treatments
on the phenolics and water holding capacity in wheat
bran.” 2011. Masters Thesis, University of Minnesota. Accessed February 28, 2021.
http://purl.umn.edu/120086.
MLA Handbook (7th Edition):
Guo, Mufan. “Effects of chemical, enzymatic and mechanical treatments
on the phenolics and water holding capacity in wheat
bran.” 2011. Web. 28 Feb 2021.
Vancouver:
Guo M. Effects of chemical, enzymatic and mechanical treatments
on the phenolics and water holding capacity in wheat
bran. [Internet] [Masters thesis]. University of Minnesota; 2011. [cited 2021 Feb 28].
Available from: http://purl.umn.edu/120086.
Council of Science Editors:
Guo M. Effects of chemical, enzymatic and mechanical treatments
on the phenolics and water holding capacity in wheat
bran. [Masters Thesis]. University of Minnesota; 2011. Available from: http://purl.umn.edu/120086
University of Minnesota
24.
Jilek, Margaret L.
Development of an high performance liquid
chromatography-mass spectrometry.
Degree: 2012, University of Minnesota
URL: http://purl.umn.edu/122128
University of Minnesota M.S. thesis. February 2012.
Major Food science. Advisor: Mirko Bunzel PhD.. 1 computer file
(PDF); v, 84 pages, appendix p. 75-84.
Summary abstract not available.
Subjects/Keywords: Food science
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APA (6th Edition):
Jilek, M. L. (2012). Development of an high performance liquid
chromatography-mass spectrometry. (Masters Thesis). University of Minnesota. Retrieved from http://purl.umn.edu/122128
Chicago Manual of Style (16th Edition):
Jilek, Margaret L. “Development of an high performance liquid
chromatography-mass spectrometry.” 2012. Masters Thesis, University of Minnesota. Accessed February 28, 2021.
http://purl.umn.edu/122128.
MLA Handbook (7th Edition):
Jilek, Margaret L. “Development of an high performance liquid
chromatography-mass spectrometry.” 2012. Web. 28 Feb 2021.
Vancouver:
Jilek ML. Development of an high performance liquid
chromatography-mass spectrometry. [Internet] [Masters thesis]. University of Minnesota; 2012. [cited 2021 Feb 28].
Available from: http://purl.umn.edu/122128.
Council of Science Editors:
Jilek ML. Development of an high performance liquid
chromatography-mass spectrometry. [Masters Thesis]. University of Minnesota; 2012. Available from: http://purl.umn.edu/122128
Cornell University
25.
Zhang, Xi.
ANTI-CANCER ACTIVITIES OF URSOLIC ACID IN HUMAN BREAST CANCER CELLS THROUGH NRF2 PATHWAY REGULATION.
Degree: PhD, Food Science and Technology, 2018, Cornell University
URL: http://hdl.handle.net/1813/59279
► Breast cancer is the most diagnosed cancers among American women. The oxidative stress from an imbalance between reactive oxidants and antioxidants is associated with carcinogenesis…
(more)
▼ Breast cancer is the most diagnosed cancers among American women. The oxidative stress from an imbalance between reactive oxidants and antioxidants is associated with carcinogenesis and is an important risk factor for breast cancer. Nrf2, a transcription factor, responds to oxidative and electrophilic stress. However, Nrf2 plays dual roles in carcinogenesis: in normal and premalignant cells, activation of Nrf2 would weaken further oxidation and prevent carcinogenesis; in malignant cells, overexpression of Nrf2 could protect tumor cells from cytotoxic effects of elevated endogenous reactive oxygen species. The beneficial or detrimental effects of Nrf2 also depends on environmental conditions. Ursolic Acid (UA), a natural pentacyclic triterpenoid widely distributed in fruits, herbs and spices, has been reported to have a strong anti-proliferative activity towards human breast cancer cells including malignant MDA-MB-231 human breast cancer cells. However, it is not known whether UA has effects on Nrf2 in MDA-MB-231 human breast cancer cells. In this study, UA inhibited the expression of Nrf2 and its phosphorylated form (phosphor S40) p-Nrf2 in MDA-MB-231 human breast cancer cells in whole cells and nucleus. The elevation in NQO1, the Nrf2 downstream antioxidant enzymes, and, the reduction in Keap1, the Nrf2 repressor, were also observed. After a 12 h pretreatment with EGF, the p-EGFR and total cellular and nuclear p-Nrf2 in MDA-MB-231 human breast cancer cells were induced but no significant differences were observed in total cellular and nuclear Nrf2 expressions. It may indicate EGFR phosphorylation might be an upstream for p-Nrf2. Tamoxifen, a selective ER modulator approved drug in the US to reduce breast cancer risk, has been proved to be an effective treatment in metastatic breast cancer and the tamoxifen adjuvant therapy reduced breast cancer recurrence and death. However, the tamoxifen resistance is a critical challenge for the treatment. We compared the constitutive expressions of Nrf2 in ER positive MCF-7 human breast cancer cells and tamoxifen-resistant MCF-7 cells (MCF-7TamR). Nrf2 and p-Nrf2 were overexpressed in MCF-7TamR cells. Its downstream proteins SOD1 and NQO1 in MCF-7TamR cells was distinctly higher in MCF-7TamR cells than in parental MCF-7 cells. The expression level of Keap1, the cytosolic repressor of Nrf2, was much lower in MCF-7TamR cells. The results suggested that Nrf2/ARE pathway might be therapeutic target to overcome tamoxifen resistance in human breast cancers. UA significantly inhibited the expression of Nrf2 and its phosphorylated form (phosphor S40) p-Nrf2 in MCF-7 and MCF-7TamR human breast cancer cells. The inhibitory effects of UA on NQO1 and SOD1 were also shown in cells. A stronger anti-proliferative activity against MCF-7TamR cells than parental MCF-7 cells at the concentration of 9 µM and higher was shown. The significant differences in Nrf2 inhibition by UA between MCF-7 and MCF-7TamR cells were also observed. It suggested that the anti-proliferative effect of UA might be…
Advisors/Committee Members: Liu, Rui-Hai (chair), Brenna, James Thomas (committee member), Gan, Susheng (committee member).
Subjects/Keywords: Food science
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APA (6th Edition):
Zhang, X. (2018). ANTI-CANCER ACTIVITIES OF URSOLIC ACID IN HUMAN BREAST CANCER CELLS THROUGH NRF2 PATHWAY REGULATION. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/59279
Chicago Manual of Style (16th Edition):
Zhang, Xi. “ANTI-CANCER ACTIVITIES OF URSOLIC ACID IN HUMAN BREAST CANCER CELLS THROUGH NRF2 PATHWAY REGULATION.” 2018. Doctoral Dissertation, Cornell University. Accessed February 28, 2021.
http://hdl.handle.net/1813/59279.
MLA Handbook (7th Edition):
Zhang, Xi. “ANTI-CANCER ACTIVITIES OF URSOLIC ACID IN HUMAN BREAST CANCER CELLS THROUGH NRF2 PATHWAY REGULATION.” 2018. Web. 28 Feb 2021.
Vancouver:
Zhang X. ANTI-CANCER ACTIVITIES OF URSOLIC ACID IN HUMAN BREAST CANCER CELLS THROUGH NRF2 PATHWAY REGULATION. [Internet] [Doctoral dissertation]. Cornell University; 2018. [cited 2021 Feb 28].
Available from: http://hdl.handle.net/1813/59279.
Council of Science Editors:
Zhang X. ANTI-CANCER ACTIVITIES OF URSOLIC ACID IN HUMAN BREAST CANCER CELLS THROUGH NRF2 PATHWAY REGULATION. [Doctoral Dissertation]. Cornell University; 2018. Available from: http://hdl.handle.net/1813/59279
Cornell University
26.
Patino, Marcela.
EVALUATION OF FORWARD OSMOSIS AND THERMAL CONCENTRATION FOR QUALITY RETENTION OF CHERRY JUICE AND CONCENTRATE.
Degree: M.S., Food Science and Technology, Food Science and Technology, 2017, Cornell University
URL: http://hdl.handle.net/1813/51573
► Concentration optimization of cherry juice to 60°Brix was evaluated with forward osmosis (FO) at 26-35°C, and thermal evaporation (TC) under high vacuum at 70°C. Sensory…
(more)
▼ Concentration optimization of cherry juice to 60°Brix was evaluated with forward osmosis (FO) at 26-35°C, and thermal evaporation (TC) under high vacuum at 70°C. Sensory evaluation of juices was conducted by discrimination and descriptive tests. A 10°C increase in temperature in FO concentration increased water flux by 35% and decreased concentration time by 19%. FO yielded higher initial retention of anthocyanins and red color, and similar sensory properties compared to TC. A 12-week shelf life study at room temperature of control, FO and TC samples included analysis of brix, color, phenolics, total anthocyanin, viscosity and major anthocyanins. Stability of anthocyanins and red color in reconstituted (13oBrix) cherry juice samples did not present significant differences due to the concentration process. Anthocyanins and red color losses over time were significantly higher when juices were stored as concentrate. Additional studies on the effect of ascorbic and added flavonoids on anthocyanin stability are recommended.
Advisors/Committee Members: Padilla-Zakour, Olga (chair), Gomez, Miguel (committee member).
Subjects/Keywords: Food science
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APA (6th Edition):
Patino, M. (2017). EVALUATION OF FORWARD OSMOSIS AND THERMAL CONCENTRATION FOR QUALITY RETENTION OF CHERRY JUICE AND CONCENTRATE. (Masters Thesis). Cornell University. Retrieved from http://hdl.handle.net/1813/51573
Chicago Manual of Style (16th Edition):
Patino, Marcela. “EVALUATION OF FORWARD OSMOSIS AND THERMAL CONCENTRATION FOR QUALITY RETENTION OF CHERRY JUICE AND CONCENTRATE.” 2017. Masters Thesis, Cornell University. Accessed February 28, 2021.
http://hdl.handle.net/1813/51573.
MLA Handbook (7th Edition):
Patino, Marcela. “EVALUATION OF FORWARD OSMOSIS AND THERMAL CONCENTRATION FOR QUALITY RETENTION OF CHERRY JUICE AND CONCENTRATE.” 2017. Web. 28 Feb 2021.
Vancouver:
Patino M. EVALUATION OF FORWARD OSMOSIS AND THERMAL CONCENTRATION FOR QUALITY RETENTION OF CHERRY JUICE AND CONCENTRATE. [Internet] [Masters thesis]. Cornell University; 2017. [cited 2021 Feb 28].
Available from: http://hdl.handle.net/1813/51573.
Council of Science Editors:
Patino M. EVALUATION OF FORWARD OSMOSIS AND THERMAL CONCENTRATION FOR QUALITY RETENTION OF CHERRY JUICE AND CONCENTRATE. [Masters Thesis]. Cornell University; 2017. Available from: http://hdl.handle.net/1813/51573
Cornell University
27.
Buehler, Ariel.
Spore Wars: Tools to Identify, Predict, and Prevent Dairy Spoilage.
Degree: PhD, Food Science and Technology, 2018, Cornell University
URL: http://hdl.handle.net/1813/59730
► Microbial spoilage is an important aspect of food loss and can occur in products that have been heat-treated and are stored refrigerated, such as dairy…
(more)
▼ Microbial spoilage is an important aspect of
food loss and can occur in products that have been heat-treated and are stored refrigerated, such as dairy products. Routes of contamination for dairy spoilage organisms include presence in raw materials and survival during processing (generally Gram-positive sporeformers) and post-processing contamination (caused by Gram-negative bacteria, yeast and molds). Given the multiple contamination pathways across the dairy processing continuum, a holistic approach is required to address dairy spoilage. To identify, predict, and prevent dairy spoilage, the studies reported here focused on (i) the application of modern molecular approaches to understand the types of fungi in dairy products and facilitate source tracking along the processing continuum in a standardized method, (ii) the development of a stochastic model and a challenge study protocol to allow industry to better evaluate spoilage control strategies for post-pasteurization fungal contamination and assess the value of these strategies quantitatively, and (iii) the development of a stochastic model to understand the effect of sporeformer contamination over the entire processing continuum and quantitatively assess the effect of spoilage control strategies. Our data revealed that dairy-relevant fungi represent a broad diversity over multiple phyla. Molecular subtyping approaches, namely ITS sequencing, are a useful tool for fungal identification. Moreover, we demonstrated that ITS sequencing can be used for fungal contamination source tracking along the processing continuum, especially for over-represented subtypes. In our stochastic model based on mold post-pasteurization contamination of yogurt, we estimated consumer exposure to visible mold based on a proof-of-concept approach using air plate samples to estimate initial mold contamination rates. This model estimated that 550 +/- 25.2 consumers would be exposed to visible mold growth for every 1 million cups of yogurt produced when no fungal inhibitor was used in the yogurt formulation. Our challenge study protocol developed a method for industry to better evaluate novel spoilage control strategies, such as protective cultures, and revealed that the two protective cultures we evaluated retarded mold, but not yeast growth in Greek yogurt. Finally, our second stochastic model provided a way to model spoilage due to psychrotolerant sporeformers in fluid milk throughout the processing continuum, from the dairy farm to the end of shelf-life and predicted that the mean concentration of psychrotolerant sporeformers in fluid milk at 21 days of storage at 6C is 4.54 +/- 1.71 Log10CFU/mL. Our model also revealed ways to quantitatively assess intervention strategies (e.g., microfiltration) to reduce dairy spoilage through the use of what-if scenarios. Overall, these studies broaden our understanding of dairy spoilage organisms. The combination of molecular subtyping and stochastic modeling represents powerful tools the dairy industry can adopt to (i) achieve more accurate estimates…
Advisors/Committee Members: Wiedmann, Martin (chair), Grohn, Yrjo Tapio (committee member), Miller, Dennis Dean (committee member).
Subjects/Keywords: Food science
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APA (6th Edition):
Buehler, A. (2018). Spore Wars: Tools to Identify, Predict, and Prevent Dairy Spoilage. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/59730
Chicago Manual of Style (16th Edition):
Buehler, Ariel. “Spore Wars: Tools to Identify, Predict, and Prevent Dairy Spoilage.” 2018. Doctoral Dissertation, Cornell University. Accessed February 28, 2021.
http://hdl.handle.net/1813/59730.
MLA Handbook (7th Edition):
Buehler, Ariel. “Spore Wars: Tools to Identify, Predict, and Prevent Dairy Spoilage.” 2018. Web. 28 Feb 2021.
Vancouver:
Buehler A. Spore Wars: Tools to Identify, Predict, and Prevent Dairy Spoilage. [Internet] [Doctoral dissertation]. Cornell University; 2018. [cited 2021 Feb 28].
Available from: http://hdl.handle.net/1813/59730.
Council of Science Editors:
Buehler A. Spore Wars: Tools to Identify, Predict, and Prevent Dairy Spoilage. [Doctoral Dissertation]. Cornell University; 2018. Available from: http://hdl.handle.net/1813/59730
28.
Van der Westhuizen, Hendrik Schalk.
Operational enhancement of an upflow anaerobic sludge blanket reactor treating fog-reduced grain distillery wastewater.
Degree: MScFoodSc, Food Science, 2014, Stellenbosch University
URL: http://hdl.handle.net/10019.1/86423
► ENGLISH ABSTRACT: Waste generated by the distillery industry is a major ecological concern and disposal thereof without a suitable treatment can have damaging effects on…
(more)
▼ ENGLISH ABSTRACT: Waste generated by the distillery industry is a major ecological concern and disposal
thereof without a suitable treatment can have damaging effects on the environment. The
characteristics of this type of wastewater are highly variable and dependent on the raw
material used and production process followed. Grain distillery wastewater (GDWW) is
also rich in fats, oils and grease (FOG). Successful treatments of distillery wastewater and
GDWW have been reported using an upflow anaerobic sludge blanket (UASB) reactor
technology. The aim of this study was to investigate the ability of lab-scale UASB reactor
to treat FOG-reduced GDWW and the subsequent enhancement thereof following an
unique feeding strategy approach. Firstly, a coagulation/flocculation-centrifugation step
was developed to obtain FOG-reduced GDWW. Secondly, the efficiency of a lab-scale
UASB reactor was investigated treating FOG-reduced GDWW at pre-determined
operational parameters as well as the verification of biomass acclimatisation. Lastly, the
effect of a unique feeding strategy of FOG-reduced GDWW to lab-scale UASB reactor
granules was investigated in terms of COD, FOG-reduction and biomass acclimatisation.
It was found that a coagulation/flocculation-centrifugation treatment removed
sufficient amounts of FOG and TSS from GDWW. Different commercially available
coagulation/flocculation products were evaluated whilst used in combination with a
centrifugation step for improved sedimentation and separation. The FOG removal remained between 90 and 97% for the ferric chloride (FeCl3) and Ferrifloc 1820
treatments, respectively, whereas the TSS removal ranged between 56 and 93%,
respectively. The use of a high molecular weight polymer (Ultrafloc 5000) and an
aluminium chlorohydrate (Ultrafloc 3800) proved to be less effective in terms of FOG
removal efficiency, ranging from 72 to 86%. It was decided to pre-treat GDWW with FeCl3
in combination with centrifugation to obtain FOG-reduced GDWW for subsequent UASB
reactor treatment investigations.
The FOG-reduced GDWW was fed into a laboratory-scale UASB reactor (2 L) over
a period of 331 days. During the operational period different feeding parameters were
attained to establish the ability of the UASB reactor to efficiently treat FOG-reduced
GDWW. The COD removal increased from 60 to 85% at an organic loading rate (OLR) of
ca. 5.5 kgCOD.m-3.d-1 (pH = 7.5) whilst FOG removal remained between 45 and 70%.
COD removal increased to 90% with the attainment of an OLR of ca.10 kgCOD.m-3.d-1
(pH = 7.5) whereas FOG removal remained in the region of 55 and 65%. COD and FOG
removal remained above 85% and 50%, respectively, when substrate pH was decreased to 6.50 (OLR ca. 10 kgCOD.m-3.d-1). A granule activity test was performed on seed and
FOG-reduced GDWW fed granules to determine biomass acclimatisation. FOG-reduced
GDWW fed granules showed higher activity in terms of methane production rate and
cumulative methane production suggesting biomass acclimatisation.
The…
Advisors/Committee Members: Sigge, G. O., Britz, T. J., Stellenbosch University. Faculty of AgriSciences. Dept. of Food Science..
Subjects/Keywords: Food science
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APA (6th Edition):
Van der Westhuizen, H. S. (2014). Operational enhancement of an upflow anaerobic sludge blanket reactor treating fog-reduced grain distillery wastewater. (Masters Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/86423
Chicago Manual of Style (16th Edition):
Van der Westhuizen, Hendrik Schalk. “Operational enhancement of an upflow anaerobic sludge blanket reactor treating fog-reduced grain distillery wastewater.” 2014. Masters Thesis, Stellenbosch University. Accessed February 28, 2021.
http://hdl.handle.net/10019.1/86423.
MLA Handbook (7th Edition):
Van der Westhuizen, Hendrik Schalk. “Operational enhancement of an upflow anaerobic sludge blanket reactor treating fog-reduced grain distillery wastewater.” 2014. Web. 28 Feb 2021.
Vancouver:
Van der Westhuizen HS. Operational enhancement of an upflow anaerobic sludge blanket reactor treating fog-reduced grain distillery wastewater. [Internet] [Masters thesis]. Stellenbosch University; 2014. [cited 2021 Feb 28].
Available from: http://hdl.handle.net/10019.1/86423.
Council of Science Editors:
Van der Westhuizen HS. Operational enhancement of an upflow anaerobic sludge blanket reactor treating fog-reduced grain distillery wastewater. [Masters Thesis]. Stellenbosch University; 2014. Available from: http://hdl.handle.net/10019.1/86423
Stellenbosch University
29.
Munhuewyi, Karen.
Postharvest losses and changes in quality of vegetables from retail to consumer : a case study of tomato, cabbage and carrot.
Degree: MScFoodSc, Food Science, 2012, Stellenbosch University
URL: http://hdl.handle.net/10019.1/71946
► ENGLISH ABSTRACT: Postharvest losses of three different vegetables (tomato - a fruit, cabbage - a leaf and carrot - a root vegetable) were investigated directly…
(more)
▼ ENGLISH ABSTRACT: Postharvest losses of three different vegetables (tomato - a fruit, cabbage - a leaf and carrot - a root vegetable) were investigated directly after retail purchasing and during consumer simulated storage. To conduct this study, three retail outlets (2 supermarkets and an outdoor market) were selected in Stellenbosch, South Africa. Retail prices of each vegetable were recorded from each respective Outlet. Surrounding environmental conditions (air temperature and relative humidity) at retail and during simulated consumer storage were also monitored. Vegetable postharvest losses were determined by quantifying the incidence of physical loss and changes in physico-chemical properties (colour, firmness, weight loss, ascorbic acid, total pigments, total soluble solids, titratable acid and proximate composition) over time. The percentage losses observed were then used to estimate the associated economic and environmental resource impacts of postharvest vegetable losses at the national level.
Vegetable losses immediately at retail purchase were 14.56%, 21.21% and 17.93% for tomato, cabbage and carrot, respectively. The estimated combined volume lost for all three vegetables at national level was approximately 26 460 t valued at R33.70 million. Overall economic loss was highest for tomatoes and least for carrots. The magnitude of the losses observed differed for all the outlets. Vegetable losses were mostly high for the produce from the outdoor market compared to the supermarkets during storage. Throughout the whole trial, mechanical damage accounted for at least 50 to 70% of the losses while the remainder was due to decay and insect damage. Post retail storage temperature; ambient (22–25ºC) vs. cold store (0ºC and 10–12 ºC) had a significant (P<0.05) effect on the vegetable losses. This was for both quantitative and qualitative attributes. Losses for tomato and cabbage were 18.52% and 16.67% after 3 days while carrot losses were 11.83% at 7 days after having been kept in the recommended respective cold storage temperatures. Ambient storage losses were also lowest for carrots at 22.53% after 7 days, while tomato and cabbage losses stood at 24.27% and 34.34% after 3 days of storage, respectively. Vegetable firmness generally decreased while weight loss increased with storage time. Colour development increased favourably at ambient temperature for the tomato whereas for cabbage and carrot better colour retention was observed in the cold storage. Chemical changes for all three vegetables were also most pronounced at ambient temperature with significant (P<0.05) losses observed for ascorbic acid. Changes were also noted for total pigments, soluble solids and acidity, however there was no common significant trend for all three vegetables.
Estimates of carbon dioxide emissions reveal that postharvest vegetable losses contribute to unwarranted emissions of at least 1.37 – 13.77 million tonnes of carbon dioxide equivalents (CO2eq.) at the national level. The losses are also accompanied by wastage of approximately…
Advisors/Committee Members: Opara, U. L., Sigge, G. O., Stellenbosch University. Faculty of AgriSciences. Dept. of Food Science..
Subjects/Keywords: Food science
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APA (6th Edition):
Munhuewyi, K. (2012). Postharvest losses and changes in quality of vegetables from retail to consumer : a case study of tomato, cabbage and carrot. (Masters Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/71946
Chicago Manual of Style (16th Edition):
Munhuewyi, Karen. “Postharvest losses and changes in quality of vegetables from retail to consumer : a case study of tomato, cabbage and carrot.” 2012. Masters Thesis, Stellenbosch University. Accessed February 28, 2021.
http://hdl.handle.net/10019.1/71946.
MLA Handbook (7th Edition):
Munhuewyi, Karen. “Postharvest losses and changes in quality of vegetables from retail to consumer : a case study of tomato, cabbage and carrot.” 2012. Web. 28 Feb 2021.
Vancouver:
Munhuewyi K. Postharvest losses and changes in quality of vegetables from retail to consumer : a case study of tomato, cabbage and carrot. [Internet] [Masters thesis]. Stellenbosch University; 2012. [cited 2021 Feb 28].
Available from: http://hdl.handle.net/10019.1/71946.
Council of Science Editors:
Munhuewyi K. Postharvest losses and changes in quality of vegetables from retail to consumer : a case study of tomato, cabbage and carrot. [Masters Thesis]. Stellenbosch University; 2012. Available from: http://hdl.handle.net/10019.1/71946
Stellenbosch University
30.
Caleb, Oluwafemi James.
Modified atmosphere packaging of pomegranate arils.
Degree: PhD, Food Science, 2013, Stellenbosch University
URL: http://hdl.handle.net/10019.1/80198
► ENGLISH ABSTRACT: Modified atmosphere packaging (MAP) is a dynamic process of altering gaseous composition inside a package. It relies on the interaction between the respiration…
(more)
▼ ENGLISH ABSTRACT: Modified atmosphere packaging (MAP) is a dynamic process of altering gaseous composition
inside a package. It relies on the interaction between the respiration rate (RR) of the
produce, and the transfer of gases through the packaging material. These two processes are
dependent on numerous factors such as storage temperature, film thickness and surface
area, produce weight as well as free headspace within the pack. Therefore, in order to
achieve the desired modified atmosphere in a given package, it is important to understand
the three basic disciplines of MAP, namely produce physiology, polymer engineering, and
converting technology.
In this study the effects of storage conditions and duration on physiological responses i.e.
respiration (RR) and transpiration rate (TR) of two pomegranate cultivars ‘Acco’ and
‘Herskawitz’, were investigated and mathematical models were developed to predict these
physiological responses at given time and storage conditions. The result of this study
showed that RR of whole pomegranate fruit was significantly higher than that of fresh arils,
and that temperature had a significant impact on the RR of both whole fruit and fresh arils.
The influence of time, and the interaction between temperature and time also had significant
influences on RR of fresh pomegranate arils. These findings highlight the significance of
maintaining optimal cold-storage condition for packaged arils or whole fruit along the supply
chain. In addition, mathematical models based on the Arrhenius-type equation and the
power function equation coupled with Arrhenius-type equation accurately predicted the
effect of temperature and the influence of time and temperature on the RR of fresh
pomegranate arils for both cultivars. Furthermore, the results of experimental and model prediction studies showed that both
relative humidity (RH) and storage temperature had significant effects on TR. RH was the
variable with the greatest influence on TR, and it was observed that arils were best kept at
5°C and 96% RH to maintain quality for 8 days. The applicability of the transpiration model
developed was validated based on prediction of TR of pomegranate arils under different
combinations of storage conditions. The model adequately predicted TR and provides a
useful tool towards understanding the rate of water loss in fresh pomegranate arils as
affected by storage conditions and duration. The effect of passive-MAP engineering design parameters as a function of produce weight
contained, storage temperature and duration on fresh pomegranate arils was investigated.
The result showed that produce weight of aril content, temperature and the interaction
between temperature and time had slight but insignificant effects on measured
physicochemical quality attributes. However, headspace gas concentration was significantly
influenced by produce weight and storage temperature. Oxygen (O2) composition decline
below 2% after day 3 and 5 at 15 and 10 ºC, respectively, while samples at 5 °C did…
Advisors/Committee Members: Opara, U. L., Manley, M., Mahajan, P. V., Stellenbosch University. Faculty of AgriSciences. Dept. of Food Science..
Subjects/Keywords: Food science
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APA (6th Edition):
Caleb, O. J. (2013). Modified atmosphere packaging of pomegranate arils. (Doctoral Dissertation). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/80198
Chicago Manual of Style (16th Edition):
Caleb, Oluwafemi James. “Modified atmosphere packaging of pomegranate arils.” 2013. Doctoral Dissertation, Stellenbosch University. Accessed February 28, 2021.
http://hdl.handle.net/10019.1/80198.
MLA Handbook (7th Edition):
Caleb, Oluwafemi James. “Modified atmosphere packaging of pomegranate arils.” 2013. Web. 28 Feb 2021.
Vancouver:
Caleb OJ. Modified atmosphere packaging of pomegranate arils. [Internet] [Doctoral dissertation]. Stellenbosch University; 2013. [cited 2021 Feb 28].
Available from: http://hdl.handle.net/10019.1/80198.
Council of Science Editors:
Caleb OJ. Modified atmosphere packaging of pomegranate arils. [Doctoral Dissertation]. Stellenbosch University; 2013. Available from: http://hdl.handle.net/10019.1/80198
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