In order to investigate the efficacy of induced electric field (IEF) in sterilizing raw milk and the effect on its physicochemical properties, milk samples were treated by IEF at different excitation voltages (300, 400, and 500 V) and evaluated for Staphylococcus aureus and Escherichia coli counts and physicochemical properties. Meanwhile, changes in acidity and total bacterial count were minored during storage. Results indicated that the outlet endpoint temperature of milk increased with the increase in excitation voltage, and so did the efficacy of IEF in inactivating S. aureus and E. coli. The efficacy of reducing the microbial level in raw milk was higher than that of traditional heat treatment and high-temperature short-time pasteurization. IEF had no significant effect on the pH, fat, soluble solids, casein, or lactoferrin content of milk (P > 0.05), nor did it destroy milk nutrients. Moreover, IEF effectively delayed the increase in acidity and extended the shelf-life of milk stored at 4 ℃ by about 6 days. This study provides a new solution for high-quality sterilization and shelf-life prolongation of raw milk.

The sterilization operation in food production is a key process to ensure the safety of food products, and most existing technologies for food sterilization utilizes thermal and/or non-thermal effects. Conventional heat sterilization requires a heat transfer medium, which is completed in a certain period of time at a certain temperature. Electric field processing, a non-conventional food processing technology which utilizes both thermal and non-thermal effects, can reduce the effective temperature threshold and time of conventional heat sterilization, thereby better retaining the nutritional value of foods with less impact on the sensory quality, flavor and color. This paper reviews the principles of ohmic heating sterilization, high-voltage pulsed electric field sterilization and induced electric field sterilization as well as the frontiers and progress in these sterilization technologies in the food industry, discusses the characteristics and differences between the current electric field technologies, and presents an outlook on their future development.

With the development of modern agricultural technology and the in-depth research of the biological effect of magnetic field, magnetic field technology has been widely used in various fields of agricultural science. Appropriate magnetic field conditions such as proper intensity, waveform, and frequency can give rise to specific non-thermal effects on agricultural raw materials, which can regulate the metabolism, respiration and mass and heat transfer efficiency of biological tissues and cells, mainly by influencing water cluster, cell morphology, biomolecular activity, and gene expression. Therefore, compared with other physical processing methods, its effects manifest more slowly. Moreover, the same magnetic field parameters could show different effects on different processed objects. At present, magnetic field technology has been verified and applied in the field of agricultural products processing, mainly including assistance in the preservation, sterilization, fermentation, and extraction of agricultural products. This article summarizes the current status of research and application of magnetic field biochemical technology in agricultural products processing, and discusses the existing problems and future trends, which will provide a reference for researchers interested in the application of this technology in the agricultural field.

Thawing is an important unit operation in the processing of frozen meat. Some of the major concerns for its application are thawing duration, temperature uniformity, juice loss, cooking loss, freshness, texture characteristics and taste changes. Good thawing quality for frozen meat can be obtained by choosing appropriate thawing technologies and processing parameters. The traditional thawing technologies include air thawing and water immersion thawing, while several novel physical field thawing methods have been developed include microwave thawing, radio-frequency thawing, infrared thawing and ohmic thawing. The microwave and radio-frequency methods, which both utilize high-frequency electromagnetic wave as excitation source, have seen increasing application in the field of frozen meat processing because of short operating time and high efficiency. This article reviews dielectric thawing technology, summarizes its key influential factors, discusses the changes in meat quality during the dielectric thawing process, and puts forward some thoughts regarding the common problems and future research directions in dielectric thawing.