Centre of Food Safety & Innovation, University of Tasmania, Private Bag 54, Sandy Bay, Tasmania, 7005, Australia.
Department of Food Science and Technology, University of Nebraska-Lincoln, 1901 N 21st St, Lincoln, NE, 68588, United States.
Food Microbiol. 2021 Aug;97:103738. doi: 10.1016/j.fm.2021.103738. Epub 2021 Jan 12.
Paneer is a fresh, soft ready-to-eat cheese that is susceptible to Listeria monocytogenes contamination, exemplified by product recalls in Australia, Canada, and the USA. Previous research demonstrates that L. monocytogenes grows in paneer, however there are no paneer-specific predictive models that quantify the effect of environmental conditions on L. monocytogenes viability. This study measured the viability of a five-strain cocktail of L. monocytogenes in freshly prepared paneer incubated at 4-40 °C. Growth rates were fitted with the extended Ratkowsky square root model, with growth rates ranging from 0.014 to 0.352 log CFU/h. In comparison with published models, only the ComBase L. monocytogenes broth model acceptably predicted growth (B = 1.01, A = 1.12) versus the developed model. The influence of paneer pH (5.0-6.0) and storage temperature (41-45 °C) on L. monocytogenes growth at the upper temperature growth boundary was described using a logistic model. These models provide quantitative tools to improve the safety of paneer processing conditions, shelf-life estimation, food safety management plans, and risk assessment.
印度奶酪是一种新鲜、柔软的即食奶酪，容易受到单核细胞增生李斯特菌的污染，这在澳大利亚、加拿大和美国的产品召回事件中得到了例证。先前的研究表明单核细胞增生李斯特菌在印度奶酪中生长，但目前还没有专门针对印度奶酪的预测模型来量化环境条件对单核细胞增生李斯特菌活力的影响。本研究测量了在 4-40°C 下孵育的新鲜制备的印度奶酪中，由五种单核细胞增生李斯特菌菌株组成的鸡尾酒的活菌数。使用扩展的 Ratkowsky 平方根模型拟合生长率，生长率范围为 0.014 至 0.352 log CFU/h。与已发表的模型相比，只有 ComBase 单核细胞增生李斯特菌肉汤模型能够较好地预测生长（B = 1.01，A = 1.12），而开发的模型则不然。使用逻辑模型描述了印度奶酪 pH 值（5.0-6.0）和储存温度（41-45°C）对高温生长边界处单核细胞增生李斯特菌生长的影响。这些模型为改善印度奶酪加工条件、保质期估计、食品安全管理计划和风险评估提供了定量工具。
