ABSTRACT Drying is an essential unit operation in the food industry, with novel technologies introduced day after day. This study aimed to investigate different drying methods of apple using the continuous microwave, pulsed microwave (PM), and convective hot-air (CH) with and without ultrasound (U) pretreatment. Results showed that simultaneous U – PM – CH drying significantly reduced drying time. Shrinkage of the samples decreased when microwave power and pulse ratio were increased. Bulk density reduced by increasing the U duration and pulse ratio. The maximum raise in rehydration (39.35%) was seen in the dried samples pretreated at a higher U duration (30 min). By raising the U time and microwave power, specific energy consumption reduced by 30.05 and 41.36%, respectively. Overall, the U – PM – CH drying enhanced the quality of the dried apples and could be suggested for commercial drying industries.

中文翻译：

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超声波强化对苹果对流干燥过程中连续和脉冲微波的影响

摘要 干燥是食品工业中必不可少的单元操作，日复一日地引入新技术。本研究旨在研究使用连续微波、脉冲微波 (PM) 和对流热空气 (CH) 进行和不进行超声 (U) 预处理的不同苹果干燥方法。结果表明，同时进行 U – PM – CH 干燥显着缩短了干燥时间。当微波功率和脉冲比增加时，样品的收缩率降低。通过增加 U 持续时间和脉冲比来降低体积密度。在较高 U 持续时间（30 分钟）下预处理的干燥样品中观察到再水化的最大提高（39.35%）。通过提高U时间和微波功率，单位能耗分别降低30.05%和41.36%。全面的，