Effect of temperature and inoculum size on the growth of Salmonella spp., Staphylococcus aureus, Escherichia coli O157:H7 and Listeria monocytogenes in egg products.

• Main Authors: Yang, Shu-Er, 楊淑娥
• Other Authors: Cheng-Chun Chou
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/01472064568707275562

碩士 === 國立臺灣大學 === 食品科技研究所 === 86 === Egg products such as steamed egg was one of the main vehicles of food-borne pathogens Salmonella spp., S. aureus, E. coli O157:H7 and Listeria monocytogenes can grow in the egg products. These pathogens are frequently reported to causes food-borne out breaks in many countries. Growth behavior of these food-borne pathogens in egg products stored at different temperatures were investigated in this study. Data obtained will provide valuable information to develop the proper storage condition and to assume the The results revealed that regardless of inoculation size, no significant growth of Salmonella spp., S. aureus, and E. coli O157:H7 was observed in steamed eggs and Scrambled eggs stored at 5℃for a period of 36 hr. However, a slight growth of L. monocytogenes was noted in the egg products. The test organizations showed different extents of growth in egg products when stored at 18, 22 and 37℃. In general, the growth rate was highest in egg products stored at 37℃.Both steamed and scrambled eggs can supply adequate nutrients support the growth of the organisms tested, Among the organisms tested, S. aureus was found to grow best in egg products, followed in deciding order, by Salmonella spp., E. coli O157: H7, and L. monocytogenes. In general, the growth of test organisms was better on steamed e Enterotoxin was detected from the steamed eggs and scrambled eggs which have been inoculated with S. aureus and stored at 37℃ or 22℃for various periods of the time. During the storage period, the higher the original inoculation size of S. aureus, the earlier the enterotoxin was detected from the egg products. The amount of enterotoxin detected in egg products increased as the storage time increased. Stimulation of heat resistance capability by heat shock depends on the kinds of microorganisms tested and the temperature of the subsequent heat treatments. Although heat shock was found to increase the heat tolerance of E. coli O157:H7, Salmonella spp. at 55℃ and 60℃, this heat treatment did not increase the heat resistance of E. coli O157:H7. On the other hand, the heat- shocked L. monocytogenes showed less subsceptle at 55℃while was more susceptle at 60℃than the non heat shocked cells.