Dogan Onay B, Stratton Jayne, Arciniega Ana, Clarke Jennifer, Tamplin Mark L, Bianchini Andreia, Wang Bing
Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE 68588, USA.
Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; The Food Processing Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA.
Int J Food Microbiol. 2022 Jun 2;370:109635. doi: 10.1016/j.ijfoodmicro.2022.109635. Epub 2022 Mar 17.
Primary and secondary models were developed for quantitatively characterizing the survival of Listeria monocytogenes in soy-sauce based acidified Asian style products that do not undergo a thermal treatment. The objective of this study was to quantify the effect of food matrix properties on L. monocytogenes' survival in soy sauce-based products. This quantification enables a product-specific estimation of 5-log reduction time to ensure a safe processing and management operation, to ultimately facilitate a science-based, safety-oriented product development process. A central composite design with four independent variables (pH, soy sauce, added NaCl and soluble solids) with five levels was used to plan the challenge studies on different formulations. To model microbial survival over time, different non-linear primary models were fit to the data obtained from challenge studies. The best-fit model was selected based on a series of statistical goodness-of-fit measures. Kinetic parameters estimated from the best-fit primary models were fit to response surface equations using second order polynomial regression. The best-fit primary model representative of the product formulations was a modified Weibull model. The natural logarithm of the scale parameter (δ, in h) was used as the response variable for the secondary model. This resulted in acceptable fitting compared to the observed values with R values of 0.95 and RMSE of 0.7 h. External validity of model predictions was conducted by comparing them to 5-log reduction times observed in independent challenge tests using different product formulations. Results indicated an acceptable validation with R = 0.81 and RMSE = 35 h. The present study provides quantitative tools specific for cold-fill-hold soy sauce-based products to enhance microbial safety management plans and product development.
开发了一级模型和二级模型，用于定量表征单核细胞增生李斯特菌在未经热处理的酱油基酸化亚洲风味产品中的存活情况。本研究的目的是量化食品基质特性对单核细胞增生李斯特菌在酱油基产品中存活的影响。这种量化能够针对特定产品估计5个对数减少时间，以确保安全的加工和管理操作，最终促进基于科学、以安全为导向的产品开发过程。采用具有四个自变量（pH值、酱油、添加的氯化钠和可溶性固形物）、五个水平的中心复合设计来规划不同配方的挑战研究。为了对微生物随时间的存活情况进行建模，将不同的非线性一级模型拟合到从挑战研究中获得的数据。根据一系列统计拟合优度指标选择最佳拟合模型。从最佳拟合一级模型估计的动力学参数使用二阶多项式回归拟合到响应面方程。代表产品配方的最佳拟合一级模型是修正的韦布尔模型。尺度参数（δ，单位为小时）的自然对数用作二级模型的响应变量。与观测值相比，这产生了可接受的拟合，R值为0.95，均方根误差为0.7小时。通过将模型预测结果与使用不同产品配方的独立挑战试验中观察到的5个对数减少时间进行比较，对模型预测的外部有效性进行了评估。结果表明验证结果可接受，R = 0.81，均方根误差 = 35小时。本研究提供了针对冷灌装酱油基产品的定量工具，以加强微生物安全管理计划和产品开发。
