Departamento de Fundamentación Biológica, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba, Córdoba X5000HUA, Argentina.
Department of Food Science and Technology, UIC Zoonosis y Enfermedades Emergentes ENZOEM, CeiA3, Universidad de Córdoba, 14014 Córdoba, Spain.
Food Res Int. 2023 May;167:112451. doi: 10.1016/j.foodres.2022.112451. Epub 2023 Jan 26.
Fresh-cut produces are often consumed uncooked, thus proper sanitation is essential for preventing cross contamination. The reduction and subsequent growth of Salmonella enterica sv Thompson were studied in pre-cut iceberg lettuce washed with simulated wash water (SWW), sodium hypochlorite (SH, free chlorine 25 mg/L), and peroxyacetic acid (PAA, 80 mg/L) and stored for 9 days under modified atmosphere at 9, 13, and 18 °C. Differences in reduction between SH and PAA were non-existent. Overall, visual quality, dehydration, leaf edge and superficial browning and aroma during storage at 9 °C were similar among treatments, but negative effects increased with temperature. These results demonstrated that PAA can be used as an effective alternative to chlorine for the disinfection of Salmonella spp. in fresh-cut lettuce. The growth of Salmonella enterica sv Thompson was successfully described with the Baranyi and Roberts growth model in the studied storage temperature range, and after treatment with SWW, chlorine, and PAA. Subsequently, predictive secondary models were used to describe the relationship between growth rates and temperature based on the models' family described by Bělehrádek. Interestingly, the exposure to disinfectants biased growth kinetics of Salmonella during storage. Below 12 °C, growth rates in lettuce treated with disinfectant (0.010-0.011 log CFU/h at 9 °C) were lower than those in lettuce washed with water (0.016 log CFU/h at 9 °C); whereas at higher temperatures, the effect was the opposite. Thus, in this case, the growth rate values registered at 18 °C for lettuce treated with disinfectant were 0.048-0.054 log CFU/h compared to a value of 0.038 log CFU/h for lettuce treated with only water. The data and models developed in this study will be crucial to describing the wash-related dynamics of Salmonella in a risk assessment framework applied to fresh-cut produce, providing more complete and accurate risk estimates.
新鲜切割的农产品通常未经烹饪即食用，因此适当的卫生措施对于防止交叉污染至关重要。本研究研究了在模拟洗涤水（SWW）、次氯酸钠（SH，游离氯 25mg/L）和过氧乙酸（PAA，80mg/L）洗涤后预切割的冰山生菜中，沙门氏菌汤普森亚种的减少和随后的生长情况，并在 9°C、13°C 和 18°C 下使用改良气氛储存 9 天。SH 和 PAA 之间的减少差异不存在。总体而言，在 9°C 下储存期间，处理之间的视觉质量、脱水、叶缘和表面褐变以及香气相似，但随着温度的升高，负面影响会增加。这些结果表明，PAA 可以替代氯用于新鲜切割生菜中沙门氏菌的消毒。在研究的储存温度范围内，使用 Baranyi 和 Roberts 生长模型成功描述了沙门氏菌汤普森亚种的生长情况，并且在经过 SWW、氯和 PAA 处理后。随后，使用预测性二级模型基于 Bělehrádek 描述的模型族来描述基于温度的生长速率与温度之间的关系。有趣的是，消毒剂的暴露会影响储存过程中沙门氏菌的生长动力学。在 12°C 以下，用消毒剂处理的生菜中的生长速率（9°C 时为 0.010-0.011 log CFU/h）低于用清水处理的生菜（9°C 时为 0.016 log CFU/h）；而在较高温度下，情况则相反。因此，在这种情况下，用消毒剂处理的生菜在 18°C 下登记的生长速率为 0.048-0.054 log CFU/h，而仅用水处理的生菜的生长速率为 0.038 log CFU/h。本研究中开发的数据和模型对于在应用于新鲜切割农产品的风险评估框架中描述与洗涤相关的沙门氏菌动力学将至关重要，从而提供更完整和准确的风险估计。
