Call number: LD2668 .T4 1958 T85

published_or_final_version / Zoology / Master / Master of Philosophy

Call number: LD2668 .T4 1986 S37 / Master of Science

Questionnaires (Survey into the commercial pig industry of Zambia covering the 1983-1984 financial year ; Sow card survey ; and, Abbatoir survey form) included as appendices in pocket in back. Includes bibliographical references (leaves 219-251) The research looked for simple answers to simple problems in the Zambian commercial pig industry. Due to logistical difficulties of working in a developing country it was designed to be a project that could be carried out in the third world and which did not involve reliance on sophisticated machinery or techniques.

Thesis (M.S.)--University of Delaware, 2006. / Principal faculty advisor: John Bernard, Dept. of Food & Resource Economics. Includes bibliographical references.

The purpose of this study was to assess factors that can influence the colour stability of fresh sausage products using a pork patty model system over a typical distribution and display period. Fresh sausage is usually sold in raw; and it should have minimum 7.5% meat protein and 9% total protein. Losses of meat quality were evidenced through the discolouration of meat, depletion of endogenous antioxidant activities, proliferation of spoilage microorganisms, and reduction in the meat redox potential. <p>Both ground pork and fresh pork patties were made from pork picnic shoulder. In the first study, the quality of both ground pork patties and fresh pork sausage patties decreased over time during storage at 4°C. The fresh sausages contained ingredients that could prolong their shelf life. The activities of these antioxidant enzymes in both ground pork and fresh sausage were depleted by day 5 of the display period. Ground pork, however, had significantly (p<0.05) higher activity of catalase, glutathione peroxidase (GSHPx), superoxide dismutase (SOD) and total antioxidant activity (TEAC) than fresh sausage due to the effect of the salt. Moreover, there was no significant treatment effect on microbial numbers but there was a significant (p<0.05) elevation of microbial colony forming units by day 5 of the display period. The elevation of microbial numbers by the end of the display period was consistent with the drop in redox potential that was measured near the surface of the patties at the end of the incubation period. <p>In the second study, there was no synergistic effect (p<0.05) between sodium erythorbate and lemon juice powder that were used to enhance colour stability during storage and display in terms of antioxidant activity, colour and microbiological profile. The addition of sodium erythorbate alone, however, had a significant effect (p<0.05) on catalase activity and a* values. In other words, this catalase activity was more effective in protecting against oxidation with the addition of sodium erythorbate so that the redness of the fresh sausages (a*values) was preserved. Furthermore, the combined addition of sodium erythorbate and lemon juice powder did not have any antimicrobial activity because there was no significant difference in total microbial counts (Brochothrix thermosphacta count and lactic acid bacteria) following the addition of those ingredients. The measurement of redox potential near the surface of fresh pork patties could not be conclusively correlated with the addition of non-meat ingredients or microbiological activity. However, the measurement of redox potential in the middle of fresh pork patties showed that the addition of sodium erythorbate lowered the redox of the fresh sausage B (0.05% sodium erythorbate) and D (0.25% lemon juice powder and 0.05% sodium erythorbate) compared to fresh sausage A (0.00% lemon juice powder and 0.00% sodium erythorbate).

The purpose of this study was to assess factors that can influence the colour stability of fresh sausage products using a pork patty model system over a typical distribution and display period. Fresh sausage is usually sold in raw; and it should have minimum 7.5% meat protein and 9% total protein. Losses of meat quality were evidenced through the discolouration of meat, depletion of endogenous antioxidant activities, proliferation of spoilage microorganisms, and reduction in the meat redox potential. <p>Both ground pork and fresh pork patties were made from pork picnic shoulder. In the first study, the quality of both ground pork patties and fresh pork sausage patties decreased over time during storage at 4°C. The fresh sausages contained ingredients that could prolong their shelf life. The activities of these antioxidant enzymes in both ground pork and fresh sausage were depleted by day 5 of the display period. Ground pork, however, had significantly (p<0.05) higher activity of catalase, glutathione peroxidase (GSHPx), superoxide dismutase (SOD) and total antioxidant activity (TEAC) than fresh sausage due to the effect of the salt. Moreover, there was no significant treatment effect on microbial numbers but there was a significant (p<0.05) elevation of microbial colony forming units by day 5 of the display period. The elevation of microbial numbers by the end of the display period was consistent with the drop in redox potential that was measured near the surface of the patties at the end of the incubation period. <p>In the second study, there was no synergistic effect (p<0.05) between sodium erythorbate and lemon juice powder that were used to enhance colour stability during storage and display in terms of antioxidant activity, colour and microbiological profile. The addition of sodium erythorbate alone, however, had a significant effect (p<0.05) on catalase activity and a* values. In other words, this catalase activity was more effective in protecting against oxidation with the addition of sodium erythorbate so that the redness of the fresh sausages (a*values) was preserved. Furthermore, the combined addition of sodium erythorbate and lemon juice powder did not have any antimicrobial activity because there was no significant difference in total microbial counts (Brochothrix thermosphacta count and lactic acid bacteria) following the addition of those ingredients. The measurement of redox potential near the surface of fresh pork patties could not be conclusively correlated with the addition of non-meat ingredients or microbiological activity. However, the measurement of redox potential in the middle of fresh pork patties showed that the addition of sodium erythorbate lowered the redox of the fresh sausage B (0.05% sodium erythorbate) and D (0.25% lemon juice powder and 0.05% sodium erythorbate) compared to fresh sausage A (0.00% lemon juice powder and 0.00% sodium erythorbate).

This study was conducted to develop and validate cleaning procedures for different processing equipment of varying complexity and to determine the efficacy of two different allergen tests. Following introduction of selected allergens to processing equipment, two treatments were applied - water wash or scrub/sanitize ? and a no clean was also evaluated. The equipment used consisted of a slicer, grinder, injector, vacuum tumbler, and plastic lugs. To introduce the allergen to the slicer, nine ready-to-eat hams were used. One hundred twenty-two kilograms of pork trim were ground, and a milk allergen was incorporated into the meat. The injector was contaminated with a food allergen by injecting boneless pork loins with a marinade containing soy flour. The slicer, grinder, injector, tumbler, and lugs were then subjected to randomized treatments. The results showed that the water wash and scrub/sanitize treatments did not differ significantly among the pieces of equipment tested. This study supported that both water wash and scrub/sanitize treatments can effectively removed allergens to a level below the industry threshold of 5 ppm.

Thesis (M.S.)--University of Delaware, 2009. / Principal faculty advisor: John C. Bernard, Dept. of Food & Resource Economics. Includes bibliographical references.

Best practices have previously been developed for beef slaughter and further processing operations with input from academic and industry leaders. Best practices for pork processors have not been developed, and those developed for the beef industry may not always be applicable to the operations of Small and Very Small establishments. Small and Very Small establishments warrant unique consideration in terms of financial and technological capabilities. While larger processors utilize multiple capital-intensive microbial interventions, smaller establishments often must rely on sanitary practices and more traditional interventions. In order to develop best practices for Small and Very Small pork slaughter and further processing establishments, a survey instrument seeking information on establishment and facility characteristics as well as current sanitary practices was distributed to Small and Very Small establishments in the Southwest region. Additionally, microbiological baselines were established for six Small and Very Small pork slaughter and/or further processing establishments to allow the efficacy of best practices to be assessed following implementation in each of the six plants. Survey responses revealed areas where best practice recommendation efforts may be focused, and microbiological baseline data provided insight to the condition of carcasses and environmental surfaces using current sanitary practices. Combined, the data reveal the opportunities for improvement in the food safety systems of Small and Very Small pork processing establishments.