Department of Poultry Science, Auburn University, AL 36849, USA.
Poult Sci. 2010 Jan;89(1):160-8. doi: 10.3382/ps.2009-00316.
Current egg washing practices use wash water temperatures averaging 49 degrees C and have been found to increase internal egg temperature by 6.7 to 7.8 degrees C. These high temperatures create a more optimal environment for bacterial growth, including Salmonella Enteritidis if it is present. Salmonella Enteritidis is the most common human pathogen associated with shell eggs and egg products. Its growth is inhibited at temperatures of 7.2 degrees C and below. The objective of this study was to determine if commercially washing eggs in cool water would aid in quickly reducing internal egg temperature, preserving interior egg quality, and slowing microbial growth. During 3 consecutive days, eggs were washed using 4 dual-tank wash water temperature schemes (HH = 49 degrees C, 49 degrees C; HC = 49 degrees C, 24 degrees C; CC = 24 degrees C, 24 degrees C; CH = 24 degrees C, 49 degrees C) at 2 commercial processing facilities. A 10-wk storage study followed, in which vitelline membrane strength, Haugh unit, and aerobic microorganisms and fungi (yeasts and molds) were monitored weekly. As storage time progressed, average Haugh unit values declined 14.8%, the average force required to rupture the vitelline membrane decreased 20.6%, average numbers of bacteria present on shell surfaces decreased 11.3%, and bacteria present in egg contents increased 39.5% during storage. Wash water temperature did not significantly affect Haugh unit values, vitelline membrane strength, or the numbers of aerobic microorganisms and fungi within the shell matrices of processed eggs. Results of this study indicate that incorporating cool water into commercial shell egg processing, while maintaining a pH of 10 to 12, lowers postprocessing egg temperatures and allows for more rapid cooling, without causing a decline in egg quality or increasing the presence of aerobic microorganisms and fungi for approximately 5 wk postprocessing.
目前的洗蛋方法使用的水温平均为 49°C，已发现这会使蛋内温度升高 6.7 至 7.8°C。这些高温为细菌生长创造了更理想的环境，包括如果存在的肠炎沙门氏菌。肠炎沙门氏菌是与壳蛋和蛋制品相关的最常见的人类病原体。其生长在 7.2°C 及以下温度下受到抑制。本研究的目的是确定在商业洗蛋过程中使用冷水是否有助于快速降低蛋内温度，保持蛋内品质，并减缓微生物的生长。在连续 3 天的时间里，在 2 家商业加工设施中使用 4 种双罐洗水温度方案（HH=49°C，49°C；HC=49°C，24°C；CC=24°C，24°C；CH=24°C，49°C）对鸡蛋进行了清洗。随后进行了为期 10 周的储存研究，每周监测卵黄膜强度、哈夫单位以及需氧微生物和真菌（酵母和霉菌）。随着储存时间的延长，平均哈夫单位值下降了 14.8%，破坏卵黄膜所需的平均力下降了 20.6%，蛋壳表面的平均细菌数量减少了 11.3%，而蛋内容物中的细菌数量增加了 39.5%。洗水温度并未显著影响处理后蛋壳内哈夫单位值、卵黄膜强度或需氧微生物和真菌的数量。本研究结果表明，在保持 pH 值为 10 至 12 的情况下，将冷水纳入商业壳蛋加工中，可降低加工后蛋的温度，并允许更快冷却，而不会导致蛋品质下降或在加工后约 5 周内增加需氧微生物和真菌的存在。
