Egg powders are increasingly popular ingredients, due to their functionality and compactness, in industrial food production and preparation at homes. However, there is a lack of studies that evaluate the thermal resistance of Salmonella Enteritidis PT30 and its potential surrogate Enterococcus faecium NRRL B-2354 in egg powders. This study examined the log-linear relationship between the thermal resistance of Salmonella Enteritidis (D-value) and the water activity (aw) of egg powders. The changes of aw in the egg powders with temperature were measured using a Vapor Sorption Analyzer and a high-temperature cell. The D80 ℃-value of S. Enteritidis PT30 and E. faecium inoculated in the egg powders preconditioned to three aw levels (0.3, 0.45, and 0.6) at 20 ℃ were determined using aluminum thermal death test cells. The aw values increased (P < 0.05) in all three egg powders when the temperature of the samples was raised from room temperature to 80 ℃. The D80 ℃-values ranged from 5.3 ± 0.1 to 25.9 ± 0.2 min for S. Enteritidis while 10.4 ± 0.4 to 43.8 ± 0.4 for E. faecium in samples of the three different aw levels. S. Enteritidis PT30 showed a log-linear relationship between D80 ℃-values and aw80 ℃ for the egg powders. This study contributes to our understanding of the impact of aw on the development of thermal treatments for low-moisture foods.

中文翻译：

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低水分活度对鸡蛋粉中肠炎沙门氏菌PT30和屎肠球菌热阻的影响

由于其功能性和紧凑性，蛋粉在工业食品生产和家庭制备中越来越受欢迎。然而，缺乏评估肠炎沙门氏菌 PT30 及其潜在替代物屎肠球菌 NRRL B-2354 在蛋粉中的耐热性的研究。本研究检验了肠炎沙门氏菌的热阻（D 值）与蛋粉的水分活度 (aw) 之间的对数线性关系。使用蒸汽吸附分析仪和高温池测量蛋粉中aw随温度的变化。使用铝热致死试验池测定在 20 ℃ 条件下预处理至三个 aw 水平（0.3、0.45 和 0.6）的蛋粉中肠炎沙门氏菌 PT30 和粪肠球菌的 D80 ℃ 值。aw 值增加（P < 0。05) 当样品的温度从室温升高到 80 ℃时，所有三种蛋粉中。在三种不同 aw 水平的样品中，肠炎沙门氏菌的 D80 ℃ 值范围为 5.3 ± 0.1 至 25.9 ± 0.2 分钟，而屎肠球菌的 D80 ℃ 值为 10.4 ± 0.4 至 43.8 ± 0.4。肠炎沙门氏菌 PT30 表现出蛋粉的 D80 ℃ 值和 aw80 ℃ 之间的对数线性关系。这项研究有助于我们了解 aw 对低水分食品热处理发展的影响。肠炎炎 PT30 表现出蛋粉的 D80 ℃ 值和 aw80 ℃ 之间的对数线性关系。这项研究有助于我们了解 aw 对低水分食品热处理发展的影响。肠炎炎 PT30 表现出蛋粉的 D80 ℃ 值和 aw80 ℃ 之间的对数线性关系。这项研究有助于我们了解 aw 对低水分食品热处理发展的影响。