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).
| Identifer | oai:union.ndltd.org:USASK/oai:usask.ca:etd-05022008-192634 |
| Date | 05 May 2008 |
| Creators | Kusuma, Josephine |
| Contributors | Shand, Phyllis J., Pegg, Ronald B., Murray, Drew, Korber, Darren R., Tanaka, Takuji |
| Publisher | University of Saskatchewan |
| Source Sets | University of Saskatchewan Library |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-05022008-192634/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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