Call number: LD2668 .T4 1965 A28 / Master of Science

Four strains of Listeria monocytogenes (LCDC 81-861, ATCC 19115, M1 and M2) examined in pure culture behaved similarly when exposed to a concentration of 0.5% CharSol C-10 liquid smoke by reducing Listeria numbers to an undetectable level within 4 hours post treatment. However, at the lower concentration of 0.25% liquid smoke, differences in resistance to the antimicrobial properties of smoke components become evident among these strains indicating that a level of 0.5% liquid smoke is more effective in controlling this organism. CharSol C-10 liquid smoke was used as a full strength dip treatment for beef franks surface inoculated with six strains of L. monocytogenes (LCDC 81-861, ATCC 19115, M1, M2, M5, and C6) then vacuum packaged and stored at 4 ± 1°C for 72 hours. Beef franks dipped in CharSol C-10 liquid smoke exhibited a significant (P < 0.001) reduction in L. monocytogenes numbers after 72 hours of storage at both inoculum levels of 1 x 10³ cells/ml and 1 x 10⁵ cells/ml.

No description available.

Thesis (Msc (Animal Sciences))--University of Stellenbosch, 2006. / This research had a dual purpose, firstly to study five muscles (M. biceps femoris, M. longissimus et lumborum, M. rectus femoris, M. semitendinosus and M. supraspinatus) of the blesbok (Damaliscus dorcas phillipsi) and springbok (Antidorcas marsupialis) in terms of the physical and chemical meat quality characteristics, and secondly, to investigate the effects of inorganic salt enhancement on the physical, chemical and sensory meat quality characteristics. The muscles differed significantly for the investigated characteristics, with the exception of a* value, chroma, and ash percentage, which did not differ in either blesbok or springbok. Furthermore, no muscle differences were found in fat percentage in blesbok or protein percentage in springbok meat. Muscle differences were found in the stearic acid (C18:0) composition, the percentage saturated fatty acids (SF) and the polyunsaturated: saturated fatty acid ratio (P:S) of the blesbok. Only linoleic acid (C18:2) as a percentage of the total fatty acids differed significantly amongst the springbok muscles. The shear force values were found to be significantly lower in the enhanced samples (blesbok: 25.16 vs. 43.75 N/1.27cm; and springbok: 23.96 vs. 34.89 N/1.27cm), which means that the enhanced muscles were more tender. The enhanced muscles of both species were found to have lower values for all investigated colour characteristics. Moisture values were found to be higher in all the enhanced muscles (blesbok: 76.53% vs. 74.38%; and springbok: 75.34% vs. 73.37%). The lower fat and protein contents of the enhanced muscles can possibly be ascribed to a diluent effect caused by the water added as part of the inorganic salt injection (blesbok: fat, 1.86% vs. 2.22%, protein, 19.61% vs. 21.67%; and springbok: fat, 1.84% vs. 2.14%, protein, 21.23% vs. 23.26%). Major changes in the mineral contents were expected between the two treatments and in both species the enhanced muscles had higher phosphorus, potassium, sodium and copper values, but lower magnesium, iron and zinc levels than the untreated muscles. Analytical sensory analyses were performed on the M. biceps femoris and M. longissimus et lumborum samples of both species. Tenderness and juiciness were significantly higher in the enhanced muscles. Although salty taste was significantly higher in the enhanced muscles due to the addition of the inorganic salt solution, it remained acceptable. Analytical and consumer sensory analyses were performed on blesbok and springbok M. longissimus et lumborum samples prepared in a stock mixture. The outcome of the analytical sensory analysis was similar to the analytical results reported above. The consumer sensory analysis showed that consumers preferred the enhanced blesbok and springbok muscles, with a significant improvement in consumers’ likeness of enhanced vs. untreated meat. This study provides important insights into the muscle differences of two of the most common game species currently utilised in South African meat production. It confirms that both species can be marketed as a low fat organic red meat source well capable of filling the modern consumer’s nutritional and health needs. It also shows that enhancing game meat with an inorganic salt solution might be a very useful processing tool to use to further game meat acceptability in terms of tenderness and juiciness as game meat is often experienced as being dry and less tender because of its lower fat content and the use of incorrect preparation techniques.

published_or_final_version / Zoology / Doctoral / Doctor of Philosophy

The composition and some qualitative aspects of ground beef offered for sale in Corvallis, Oregon were studied. Samples were purchased from six retail markets twice weekly throughout a six week test period. Three stores were independently owned and operated and three were chain stores. Differences in moisture, fat and protein levels of ground beef samples among the six stores and between chain and independently owned stores were statistically significant. Differences in composition between sampling days (Tuesday versus Friday) and between replicate weeks were generally not significant. Ground beef from chain stores was generally characterized by higher moisture and protein levels and lower fat levels. Thirty-two percent of all samples (50 percent of the independent stores and 14 percent of the chain stores) exceeded the legal limit of 30 percent fat. Moisture:protein ratios ranged from 2.53 to 4.24 while the average value was 3.59. About 28 percent of all samples had ratios in excess of 3.70. Differences in moisture:protein ratios between chain and independent stores were not significant. Although differences in extract-release volume (ERV) of ground beef obtained from the various stores were significant, differences between sampling days, replicate weeks and chain versus independent stores were not. Resazurin reduction times of ground beef among individual stores, between sampling days, replicate weeks and chain versus independent stores were not significantly different. The correlation between ERV and resazurin reduction time was low (r = 0.21) suggesting a poor relationship between these two procedures for assessing microbial contamination in ground beef. Differences in nonprotein nitrogen (NPN) levels of samples among stores and between sampling days were statistically significant. Only minor differences in NPN levels between store types and replicate weeks were observed. Soluble protein levels appeared to be a reflection of total protein. Iodine numbers of ground beef fat ranged from 43.7 to 53.6 and were significantly higher in ground beef purchased from chain stores. Price per pound of ground beef and price per pound of protein were significantly different among the six stores. The price per pound of meat was significantly higher in the chain stores than in the independent stores. However, price per pound of protein and price per pound of soluble protein were essentially the same for the two types of stores. Recommendations for quality control of ground beef sold at the retail level are discussed. / Graduation date: 1968

No description available.

1p. / Revised / Which is better, wooden or plastic cutting board? Recent research has confirmed the conventional belief that plastic is safer than wood for cutting meat and poultry. This article explains the reason why plastic cutting boards are better, and gives recommendations on how to keep cutting boards safe.

No description available.

No description available.