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You searched for +publisher:"Utah State University" +contributor:("Daren Cornforth"). Showing records 1 – 2 of 2 total matches.

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Utah State University

1. Racz, Julie M. Growth of Clostridium Sporogenes PA3679 in a Vacuum-Packaged Meat-Vegetable Product.

Degree: MS, Nutrition, Dietetics, and Food Sciences, 1999, Utah State University

Clostridium sporogenes PA 3679 spores were inoculated into a meat-vegetable mixture before extrusion, cooking, and vacuum packaging into "stewsticks" to simulate Clostridium botulinum growth. The experiment was a 3 x 5 x 2 x 3 factorial which determined the influence of pH, water activity, initial spore load, and storage period on spore survival. Spore levels decreased throughout storage for all treatments. Spore levels decreased linearly (P = 0.02) as water activity increased, in samples that were heated to kill vegetative cells and activate spores. Other significant interactions of heat-treated samples were observed with inoculum level (P < 0.01) and storage time (P < 0.01). Spore levels in stored products were also significantly affected by water activity* inoculum level (P = 0.03), pH * time, water activity* time (P = 0.01), inoculum level * time (P < 0.01), and water activity * inoculum levels * time (P < 0.01). The interaction between pH * water activity * time tended towards significance (P = 0.06). Most probable number estimates in nonheated samples accounted for naturally occurring viable cells and spores, and added spores and were significantly affected by the main effects of inoculum level (P < 0.01) and time (P < 0.01). The two-way interactions of water activity * inoculum level (P = 0.04), pH * inoculum level (P < 0.01),water activity * time (P < 0.01), and three-way interaction of pH * inoculum level * time (P = 0.03) were significant. Spore levels approached 102, or less (compared to an inoculum level of 106 spores per gram) due to the effects of many treatments. Some stewstick packages were observed to become "gassy" or "loose" during storage. Subsequently the stewstick packages were used to isolate microorganisms that were able to grow at water activities of 0.96-0.86, in glycerol-adjusted Rogosa agar, and were acid tolerant to pH 4.4-4.2. One produced gas in pure culture, and some produced indole. These bacteria were not destroyed by heating to 74°C for at least 30 minutes, and lowered the pH in the stewstick during storage. In conclusion, in all stewstick samples, regardless of pH or Aw, inoculated clostridial spore levels decreased during storage, apparently because spores germinated and vegetative cells subsequently died. Thus, if stewsticks are cooked to 74°C throughout, have a Aw ≤ 0.86 and pH ≤ 4.8, they appear to be safe. Advisors/Committee Members: Daren Cornforth, ;.

Subjects/Keywords: Clostridium Sporogenes PA 3679; Vacuum-Packaged; Meat-Vegetable Product; Food Microbiology; Food Processing

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APA (6th Edition):

Racz, J. M. (1999). Growth of Clostridium Sporogenes PA3679 in a Vacuum-Packaged Meat-Vegetable Product. (Masters Thesis). Utah State University. Retrieved from https://digitalcommons.usu.edu/etd/5460

Chicago Manual of Style (16th Edition):

Racz, Julie M. “Growth of Clostridium Sporogenes PA3679 in a Vacuum-Packaged Meat-Vegetable Product.” 1999. Masters Thesis, Utah State University. Accessed December 14, 2019. https://digitalcommons.usu.edu/etd/5460.

MLA Handbook (7th Edition):

Racz, Julie M. “Growth of Clostridium Sporogenes PA3679 in a Vacuum-Packaged Meat-Vegetable Product.” 1999. Web. 14 Dec 2019.

Vancouver:

Racz JM. Growth of Clostridium Sporogenes PA3679 in a Vacuum-Packaged Meat-Vegetable Product. [Internet] [Masters thesis]. Utah State University; 1999. [cited 2019 Dec 14]. Available from: https://digitalcommons.usu.edu/etd/5460.

Council of Science Editors:

Racz JM. Growth of Clostridium Sporogenes PA3679 in a Vacuum-Packaged Meat-Vegetable Product. [Masters Thesis]. Utah State University; 1999. Available from: https://digitalcommons.usu.edu/etd/5460


Utah State University

2. Rodriguez, Beatriz T. In vitro Growth of Muscle Satellite Cells Isolated from Normal and Callipyge Lambs.

Degree: MS, Nutrition, Dietetics, and Food Sciences, 1999, Utah State University

The muscle hypertrophy of lambs expressing the Callipyge phenotype is possibly linked to characteristics of their muscle satellite cells. Therefore, characteristics (proliferation, fusion %, and protein accretion) of cultured satellite cells isolated from the longissimus muscle of Callipyge (n = 3) and normal (n = 3) lambs were compared in this study. In the first experiment, we tested whether or not the lll proliferation rates differ for satellite cells isolated from Callipyge or normal sheep when cultured in the presence of different serum types (horse, normal lamb, or Callipyge lamb). The average population doubling time (PDT, h) during log phase growth was calculated for cells from each animal grown in each serum type. Population doubling time was not affected (P > .1) by the interaction of satellite cell type with serum type, or by satellite cell type. Unexpectedly, PDT was longer (P < .05) for satellite cells grown in Callipyge serum (22 h) than for cells grown in normal sheep serum (20 h) or horse serum (18 h). These results suggest that muscle hypertrophy of Callipyge lambs is not linked to intrinsic differences in satellite cell proliferation, although hypertrophy may be associated with a decreased proliferation induced by a factor in Callipyge serum. In the second experiment, we tested whether cell fusion, or protein accretion differ for cultured satellite cells isolated from Callipyge or normal sheep. DNA and protein were determined at 24, 48, 72, and 96 h after satellite cell cultures were induced to differentiate. Fusion percentage was determined in a Giemsa stained plate after 72 h in differentiation medium (Dulbecco's Modified Eagle Medium containing 1.5% of horse serum). Callipyge cultures tended (P = .14) to have higher fusion% than normal cultures exhibited, suggesting that muscle hypertrophy of Callipyge lambs may be linked to an increased tendency of satellite cells to fuse. Protein content (μg/well) and protein:DNA ratio (ng of protein/ng of DNA) were not affected by satellite cell type (P = .80 and P = .79, respectively). Thus, there was no evidence for a link between increased protein accretion and Callipyge hypertrophy. Advisors/Committee Members: Charles E. Carpenter, Noelle E. Cockett, Daren Cornforth, ;.

Subjects/Keywords: muscle hypertrophy; lambs; callipyge; satellite cells; cell fusion; protein accretion; Food Science; Nutrition

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Rodriguez, B. T. (1999). In vitro Growth of Muscle Satellite Cells Isolated from Normal and Callipyge Lambs. (Masters Thesis). Utah State University. Retrieved from https://digitalcommons.usu.edu/etd/5463

Chicago Manual of Style (16th Edition):

Rodriguez, Beatriz T. “In vitro Growth of Muscle Satellite Cells Isolated from Normal and Callipyge Lambs.” 1999. Masters Thesis, Utah State University. Accessed December 14, 2019. https://digitalcommons.usu.edu/etd/5463.

MLA Handbook (7th Edition):

Rodriguez, Beatriz T. “In vitro Growth of Muscle Satellite Cells Isolated from Normal and Callipyge Lambs.” 1999. Web. 14 Dec 2019.

Vancouver:

Rodriguez BT. In vitro Growth of Muscle Satellite Cells Isolated from Normal and Callipyge Lambs. [Internet] [Masters thesis]. Utah State University; 1999. [cited 2019 Dec 14]. Available from: https://digitalcommons.usu.edu/etd/5463.

Council of Science Editors:

Rodriguez BT. In vitro Growth of Muscle Satellite Cells Isolated from Normal and Callipyge Lambs. [Masters Thesis]. Utah State University; 1999. Available from: https://digitalcommons.usu.edu/etd/5463

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