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In this study, a tunnel-type continuous multi-physical field drying equipment was developed to combine microwave, hot air, and infrared drying technologies. The microwave source arrangement and hot air equalizing plate were optimized based on numerical simulation to enhance the uniformity of the microwave field and hot air velocity distribution. Mode 4 and opening ratio 37.70% (r = 60 mm) were had the highest electric field distribution and hot air distribution. This equipment was further used to pre-dehydrate cowpeas and the effects of microwave, hot air, and infrared on food drying properties and quality of dried samples were investigated. The results showed that the moisture content was reduced by 20% and the ΔE value greater than 5 after pre-dehydration. Microwave treatment rapidly reduced the moisture content of cowpeas. The infrared treatment significantly improved the uniformity of temperature distribution and the texture profile of the dried sample. The hot air drying increased 10 °C for the overall temperature of the food material and balanced the internal water content of the food material. This study aims to provide future researchers with insights to develop novel microwave-based continuous drying equipment for its commercial applications. [ABSTRACT FROM AUTHOR]

Food safety requires point-of-care testing (POCT) for mycotoxins, since their presence in wine significantly impacts the wine industry and poses a severe threat to human life. Traditional detection methods are usually limited to detecting one mycotoxin and cannot achieve high-throughput, automated, and rapid quantitative analysis of multiple mycotoxins in real samples. Here, we propose a portable automated microfluidic platform (PAMP) integrating a chemiluminescence (CL) imaging system and a microfluidic chip to realize POCT for multiple mycotoxins in real samples, simplifying complex manual operations, shortening the detection time, and improving the detection sensitivity. Specially, silicone films were used as substrates on microfluidic chips to incubate mycotoxin conjugations, and the streptavidin–biotin (SA-B) system and an indirect immunoassay were implemented on silicone films to improve the sensitivity of reaction results. Interestingly, these methods significantly improved detection results, resulting in sensitive detection of mycotoxins, including zearalenone (ZEA) ranging from 1 to 32 ng/mL, aflatoxin B1 (AFB1) ranging from 0.2 to 6.4 ng/mL, and ochratoxin A (OTA) ranging from 2 to 64 ng/mL. The recovery of samples reached 91.39–109.14%, which verified the reliability and practicability of the PAMP. This PAMP enables sensitive and rapid detection of multiple mycotoxins in markets or wineries that lack advanced laboratory facilities. Therefore, it is essential to develop a portable microfluidic platform for POCT to detect mycotoxins in real samples. [ABSTRACT FROM AUTHOR]

Microwaves are electromagnetic waves of specific frequencies (300 MHz–3000 GHz), whereas ultrasonic is mechanical waves of specific frequencies. Microwave and ultrasonic technology as a new processing method has been widely used in food processing fields. Combined ultrasonic and microwave technology is exploited by researchers as an improvement technique and has been successfully applied in food processing such as thawing, drying, frying, extraction, and sterilization. This paper overviews the principle and characteristics of ultrasonic‐ and microwave‐assisted food processing techniques, particularly their combinations, design of equipment, and their applications in the processing of agricultural products such as thawing, drying, frying, extraction, and sterilization. The combination of ultrasonic and microwave is applied in food processing, where microwave enhances the heating rate, and ultrasonic improves the efficiency of heat and mass transfer. The synergy of the heating effect of microwave and the cavitation effect of ultrasonic improves processing efficiency and damages the cell structure of the material. The degradation of nutrient composition and energy consumption due to the short processing time of combined ultrasonic and microwave technology is decreased. Ultrasonic technology, as an auxiliary means of efficient microwave heating, is pollution‐free, highly efficient, and has a wide range of applications in food processing. [ABSTRACT FROM AUTHOR]

In order to protect the quality of peanuts after harvest and increase the efficiency of hot-air drying, a dryer based on superposition and variable temperature control technology was built. Samples layered with a thickness of 60 mm were dried with hot air temperatures of 70 °C, 90 °C, and 110 °C. Variable temperature drying was performed in three stages, including 110 °C hot air with a sample layer thickness of 30 mm, 90 °C hot air with a sample layer thickness of 60 mm, and 70 °C hot air with a sample layer thickness of 120 mm. The change in the temperature, moisture ratio, and state were monitored during the drying process. It was found that the temperature distribution for peanuts was uneven at the beginning stage of hot-air drying, but gradually became uniform as the drying proceeded. Low-field nuclear magnetic resonance and magnetic resonance imaging (LF-NMR/MRI) analysis showed that the water in fresh peanuts was mainly distributed inside the cotyledons. The amount of free water, immobilized water, and bound water varied during the drying process, when the signal amplitudes of the free water and total water were significantly reduced, and the moisture state moved in the direction closely associated with the organic components. The results of infrared thermography and MRI showed that there was satisfactory moisture and heat diffusion uniformity for peanuts during the process. This study will provide a reference for improving the hot-air drying technology of agricultural products. [ABSTRACT FROM AUTHOR]

In order to review the research progress of energy-carrying microwave in agricultural product drying in recent years, and analyze the influence of negative pressure environment on drying behavior, this article takes the negative pressure level and drying mode of microwave drying as the main line to explain the high moisture agricultural materials in low vacuum High-degree negative pressure microwave pulse-spouted microwave vacuum drying (PS-MVD), medium vacuum degree microwave vacuum drying (microwave vacuum drying, MVD), high vacuum degree microwave vacuum freeze drying (microwave vacuum freeze drying), MVFD) drying mode and material characteristics, while discussing the innovative application of "hot air-microwave vacuum" combined drying, "microwave vacuum-vacuum impregnation" processing, and "pulse spout microwave vacuum freeze drying" process for agricultural products. [ABSTRACT FROM AUTHOR]