The effects of low-frequency ultrasonic pre-treatment in water/oil medium simulated system on the improved processing efficiency and quality of microwave-assisted vacuum fried potato chips were investigated. The water medium system (distilled water and 5% NaCl osmotic solution) and oil medium system (90 °C) were designed with different power levels of ultrasound to simulate the ultrasonic conditions. Results showed that the changes of moisture content, water loss, solid gain and dielectric properties of potato slices were facilitated by the ultrasonic treatment. LF-NMR analysis showed the binding force between the moisture and structure in the material was significantly (p < 0.05) weakened. The changes become greater with the increase of ultrasonic power levels. Microscopic channels and disruptions were induced on the microstructure by the ultrasonic treatment. The effective moisture diffusivity of vacuum fried (VF) potato chips was increased by about 56.2%-67.0% and 53.9% with the combination of microwave energy and the ultrasonic pre-treatment in water and oil medium simulated system, respectively. The oil uptake, hardness, shrinkage, total color change and water activity of vacuum fried samples were significantly (p < 0.05) decreased by the assist of microwave energy combined ultrasonic pre-treatment.

中文翻译：

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水/油介质模拟系统中的低频超声预处理对微波辅助真空油炸土豆片提高加工效率和质量的影响。

研究了水/油介质模拟系统中的低频超声预处理对微波辅助真空油炸马铃薯片提高加工效率和质量的影响。设计了水介质系统（蒸馏水和5％NaCl渗透溶液）和油介质系统（90°C），以不同的超声功率水平模拟超声条件。结果表明，超声波处理可促进马铃薯切片的水分含量，失水量，固含量和介电性能的变化。LF-NMR分析表明材料中水分和结构之间的结合力明显减弱（p ＜0.05）。随着超声功率水平的增加，变化变得更大。通过超声处理在微观结构上引起微观通道和破坏。在水和油介质模拟系统中，结合微波能量和超声预处理，真空油炸（VF）薯片的有效水分扩散率分别提高了约56.2％-67.0％和53.9％。借助微波能量联合超声预处理，真空油炸样品的吸油量，硬度，收缩率，总颜色变化和水活度显着降低（p <0.05）。