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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.

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.

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.

The induced electric field (IEF) was produced via an oscillating magnetic field, for direct heating of orange juice within a winding coil. During the process, the applied magnetic field was at the range from 0.07 to 1.43 T with 50 kHz. Then, the numerical relationships between excitation voltage, magnetic field, IEF, induced current density, magnetomotive force and energy efficiency were investigated. Since a rectangular wave of excitation voltage was applied, the sawtooth waveform of induced voltage or IEF loaded on the juice was observed. As the magnetic field increased, outlet temperature and induced current density in the juice was improved, the maximum values were 99.5°C and 0.50 A/cm2, respectively, at a conductivity 4.53 mS/cm for the residence time of 4.5 min. However, the efficiency of the process exhibited a negative correlation with the escalation of excitation voltage. At initial colony count about 4.50 log colony‐forming units/mL, the IEF pasteurization reduced all the aerobic microorganisms, molds, and yeasts in the juice, which were evaluated at detectable limits below 1 log colony‐forming units/mL. Moreover, all treatments had no significant effects on pH, total soluble solids and titratable acidity of the juice (p > 0.05). In particular, there was also no significant change in color parameters after IEF pasteurization (p > 0.05). It indicated a significant decrease in vitamin C and total phenolic content of the control groups (p > 0.05), but no significant change in carotenoid content was observed in all treated juice (p > 0.05). heating technology using IEF has the potential to the pasteurization of fruit juice. Practical applications: Induction electric field technology has progressed rapidly in the past 2 years, it can use oscillating alternating magnetic field to realize the direct heating of liquid food. The process has thermal and non‐thermal effects, at 65–70°C, within 15–30 s to achieve the commercial asepsis of acidic liquid food. After the pasteurization, it can better maintain the color and flavor of the juice. We have assembled a laboratory prototype for testing in the early stage, the processing capacity is at the range of 0–10 L/h. Currently, the system has been able to reach the pilot production scale with the processing capacity of 100–500 L/h. Through the use of highly permeable magnetic materials, the energy consumption per ton of juice processing is controlled at 120 k·Wh level for the pasteurization and is expected to achieve a larger processing capacity in the future. [ABSTRACT FROM AUTHOR]