Huang Chi-Yun, Sheen Shiowshuh, Sommers Christopher, Sheen Lee-Yan
Institute of Food Science and Technology, National Taiwan University, Taipei, Taiwan.
Eastern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, Wyndmoor, PA, United States.
Front Microbiol. 2018 Aug 14;9:1871. doi: 10.3389/fmicb.2018.01871. eCollection 2018.
Shiga toxin-producing O157:H7 (STEC) is a common contaminant in meat and poultry. We investigated the use of non-thermal high pressure processing (HPP), with or without allyl isothiocyanate (AITC) essential oil, to kill STEC in ground chicken meat. Temperature was found an important factor affecting the inactivation of STEC in addition to pressure and process time. A full factorial experiment design (4 factors × 2 levels) was used to facilitate and evaluate the effect of pressure (250-350 MPa), operation temperature (-15-4°C), AITC concentration (0.05-0.15%, w/w), and pressure-holding time (10-20 min) on the inactivation of STEC. A linear model (a polynomial equation) was developed to predict/describe those four parameters' impact on O157:H7 survival ( = 0.90), as well as a dimensionless non-linear model. Both types of models were validated with data obtained from separate experimental points. The dimensionless model also demonstrated that it may predict the lethality (defined as the log CFU/g reduction of STEC before and after treatment) reasonably well with some factors set slightly outside the design ranges (e.g., a wider application than the linear model). The results provide important information regarding STEC survival as affected by HPP (e.g., pressure, time and temperature) and AITC. With the addition of AITC, the hydrostatic pressure may be lowered to the 250-350 MPa level. Regulatory agencies and food industry may use those models for STEC risk assessment in ground chicken meat. A storage test (at 4 and 10°C, 10 days) after HPP+AITC treatment indicated that AITC may continue depressing or killing the pressure-damaged cells.
产志贺毒素的O157:H7（STEC）是肉类和禽类中常见的污染物。我们研究了使用非热高压处理（HPP），添加或不添加异硫氰酸烯丙酯（AITC）精油，来杀灭碎鸡肉中的STEC。除压力和处理时间外，温度被发现是影响STEC失活的一个重要因素。采用全因子实验设计（4个因素×2个水平）来促进和评估压力（250 - 350兆帕）、操作温度（-15 - 4°C）、AITC浓度（0.05 - 0.15%，w/w）和保压时间（10 - 20分钟）对STEC失活的影响。建立了一个线性模型（多项式方程）来预测/描述这四个参数对O157:H7存活（ = 0.90）的影响，以及一个无量纲非线性模型。两种类型的模型都用从单独实验点获得的数据进行了验证。无量纲模型还表明，在一些因素设置略超出设计范围时（例如，比线性模型有更广泛的应用），它可以较好地预测致死率（定义为处理前后STEC的对数CFU/g减少量）。结果提供了关于HPP（如压力、时间和温度）和AITC对STEC存活影响的重要信息。添加AITC后，静水压力可降至250 - 350兆帕水平。监管机构和食品行业可将这些模型用于碎鸡肉中STEC的风险评估。HPP + AITC处理后的储存试验（在4和10°C下，10天）表明，AITC可能会继续抑制或杀死压力损伤的细胞。
