Multiple sensor-type system for monitoring the microbicidal effectiveness of aseptic sterilisation processes

The present work describes a novel multiple sensor-type system for the real-time analysis of aseptic sterilisation processes employing gaseous hydrogen peroxide (H₂O₂) as a sterilant. The inactivation kinetics of Bacillus atrophaeus by gaseous H₂O₂ have been investigated by means of a methodical calibration experiment, taking into account the process variables H₂O₂ concentration, humidity and gas temperature. It has been found that the microbicidal effectiveness at H₂O₂ concentrations above 2% v/v is largely determined by the concentration itself, while at lower H₂O₂ concentrations, the gas temperature and humidity play a leading role. Furthermore, the responses of different types of gas sensors towards the influencing factors of the sterilisation process have been analysed within the same experiment. Based on a correlation established between the inactivation kinetics and the sensor responses, a calorimetric H₂O₂ sensor and a metal-oxide semiconductor (MOX) sensor have been identified as possible candidates for monitoring the microbicidal effectiveness of aseptic sterilisation processes employing gaseous H₂O₂. Therefore, two linear models that describe the relationship between sensor response and microbicidal effectiveness have been proposed.     

Determination of Electrical Parameters of Liquid Foods for Predicting Waveforms of High‐Voltage Low‐Energy Pulses

Abstract

The voltage waveform for pulsed electrical field across a batch treatment chamber was modeled as a function of voltage applied, time, and circuit elements. The shaping function was modeled by exponential decay and linear models. The model parameters were obtained from solutions of various electrical conductivity. The model parameters were determined for orange juice, apple cider, whole milk and skim milk and then waveforms were predicted and compared with experimental results for validation. Experimental data gave an acceptable fit to the model (r ² = 0.853 to 0.948). The pulse waveform can be predicted for any food by knowing electrical parameters of the foods to be processed under pulsed electrical field.     

Optimization of processing conditions for the sterilization of retorted short-rib patties using the response surface methodology

The aim of this study was to determine the optimum sterilization conditions for short-rib patties in retort trays by considering microbiological safety, nutritive value, sensory characteristics, and textural properties. In total, 27 sterilization conditions with various temperatures, times, and processing methods were tested using a 3³ factorial design. The response surface methodology (RSM) and contour analysis were applied to find the optimum sterilization conditions for the patties. Quality attributes were significantly affected by the sterilization temperature, time, and processing method. From RSM and contour analysis, the final optimum sterilization condition of the patties that simultaneously satisfied all specifications was determined to be 119.4 °C for 18.55 min using a water-cascading rotary mode. The findings of the present study suggest that using optimized sterilization conditions will improve the microbial safety, sensory attributes, and nutritional retention for retorted short-rib patties.     

果蔬汁饮料的安全控制

为给我国果蔬汁饮料的安全控制提供借鉴，对目前国内外通用的果蔬汁饮料安全控制的几种主要方法进行了综述，主要涉及到杀菌方法，警示标签制度，制定果蔬汁饮料中污染物限量标准，制定良好生产规范，卫生标准操作程序，建立实施HACCP体系等。对每种控制体系或方法的概念，内容及要求，适用范围，国内外应用现状，优缺点等内容进行了概括介绍。