Change in microbial resistance to heat in non-isothermal process of pasteurization and building of predictive model

巴氏灭菌非等温过程微生物耐热性变化及预测模型的建立

• 批准号: 12650793
• 负责人: TUCHIDO Tetsuaki
• 金额: $ 2.24万
• 依托单位: Kansai University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650793/
• 关键词: Pasteurization; Non-isothermal process; Eschericha coli; Heat resistnace; Predictive microbiology; 非定温過程; 予備保温

Recently, the construction of reliable method for evaluation of heat process and the establishment of theorctical background for determ. ining shel-life of foods have been required. We conducted this study in order to build up such a model in which the effect of non-isothermal process on the heat resistance of microorganisms was considered. Escherichia coli cells were pre-incubated at different temperatures between 0 and 45℃ before heat treatment at a lethal temperature and their resistance was evaluated. As a result, the dependency of a parameter D value, the decimal reduction time, on the pre-incubation temperature demonsirated different patterns between below and above 37℃. Above 37℃, the rate of increase in and the steady state level of D value were found to be rather high. The rate of dilution for temperature rise from pre-incubation to heat treatment afiiected the dependency of D value on the pre-incubation. To see the dependency of rate of increase in D value on the preincubation temporature, we took its Arrhenius plot from the data obtained in this study and previously by us. The results should be available for prediction of the thermal death in practical evaluation of heat processes. Furthermore, we obtained data concerning thermal death reaction by changing factors such as heating temperature, pH, and sodium chloride concentration to develop predictive equations between two factors and also between all factors by second-order and third-order regression analyses, respectively.

近年来，建立了可靠的热工过程评价方法，建立了确定热工过程的理论依据。对食品的保质期提出了要求。我们进行这项研究是为了建立一个考虑非等温过程对微生物耐热性的影响的模型。将大肠杆菌细胞在0~45℃的不同温度下预先孵育，然后在致死温度下进行热处理，并对其抗性进行评估。结果，参数D值、小数还原时间对预孵化温度的依赖关系在低于和高于37℃之间表现出不同的模式。在37℃以上，D值的上升速度和稳态水平较高。从预孵化到热处理温度升高的稀释速率反映了D值对预孵化的依赖关系。为了了解D值的增长率与孵化前温度的依赖关系，我们从本研究和之前我们获得的数据中获得了它的Arrhenius图。研究结果可用于实际热过程评价中的热死亡预测。此外，我们通过改变加热温度、pH和氯化钠浓度等因素获得了关于热死亡反应的数据，分别通过二次和三次回归分析建立了两个因素之间的预测方程和所有因素之间的预测方程。