IRTA, Food Safety Programme, Finca Camps i Armet, s/n, E-17121 Monells, Spain.
Food Microbiol. 2013 Aug;35(1):34-7. doi: 10.1016/j.fm.2013.03.001. Epub 2013 Mar 14.
To quantify the inactivation of Serratia liquefaciens exerted by high pressure processing (HPP), slices of dry-cured ham were inoculated and processed combining different levels of technological parameters: pressure (347-852 MPa), time (2.3-15.8 min) and temperature (7.6-24.4 °C) according to a central composite design. Bacterial inactivation, as logarithmic reduction, indicated that S. liquefaciens was relatively sensitive to HPP. Six log reductions were achieved in a total of 10 trials combining pressures of 600 MPa or above with different holding times and temperatures. The inactivation of S. liquefaciens was analysed through the multiple regression analysis to generate a second order polynomial equation. Pressure and time were the two factors which significantly determined the inactivation of S. liquefaciens on dry-cured ham. Temperature did not significantly affect the lethality of the process. The response surface methodology was used to determine optimum process conditions to maximize the inactivation of S. liquefaciens in the experimental range tested. The maximum inactivation of S. liquefaciens in dry-cured ham was achieved by combining a pressure of 650 MPa with a holding time of 8 min. Combinations above these values (i.e. 750 MPa for 13 min) would not significantly improve the lethality of the process.
为了量化高压处理（HPP）对液化沙雷氏菌的灭活效果，将干腌火腿切片接种并结合不同的工艺参数进行处理：压力（347-852 MPa）、时间（2.3-15.8 分钟）和温度（7.6-24.4°C），根据中心复合设计进行组合。细菌失活动力学表明，液化沙雷氏菌对 HPP 相对敏感。在总共 10 次试验中，结合压力为 600 MPa 或更高，并结合不同的保持时间和温度，实现了 6 个对数减少。通过多元回归分析对液化沙雷氏菌的失活动力学进行分析，生成二次多项式方程。压力和时间是决定干腌火腿中液化沙雷氏菌失活动力学的两个重要因素。温度对过程致死率没有显著影响。采用响应面法确定最佳工艺条件，以在试验范围内最大限度地提高液化沙雷氏菌的灭活效果。在测试的实验范围内，通过组合 650 MPa 的压力和 8 分钟的保持时间，实现了液化沙雷氏菌在干腌火腿中最大的灭活效果。高于这些值的组合（即 13 分钟时为 750 MPa）不会显著提高过程的致死率。
