The use of ultrasound and vacuum to shorten the processing time and to improve the quality of elephant apple (Dillenia indica) slices during drying was investigated. Preliminary studies were done on the application of ultrasonic vacuum energy with elephant apple slices at different temperatures (40, 50, 60, 70 and 80 °C). The best results were obtained at 60 ± 12 °C. The values for DPPH radical scavenging activity, total phenolic content and total flavonoid content of dried samples were found as 50 ± 2 μ mol of TE/g, 31 ± 1 mg GAE/g and 12 ± 1 mg quercetin/g, respectively. The effect of ultrasonic vacuum drying (UVD) was compared with the slices dried using vacuum drying (VD) and tray drying (TD). The time required to dry elephant apple slices to final moisture content of ~8.5 ± 1% (db) was 930, 870 and 690 min for TD, VD and UVD, respectively. The drying kinetics of the elephant apple slices was tested using 9 thin-layer drying models. Among the mathematical models investigated, the two term exponential model satisfactorily described the drying behavior of elephant apple slices with high R² (0.9971–0.9989) and low χ² (0.00039–0.00056) values. UVD may be a useful non-thermal technology for drying elephant apple slices, which accelerates drying kinetics as well as improves the quality of the final product.

超声波和真空的使用可以缩短加工时间并提高象苹果的质量（Dillenia indica））研究了干燥过程中的切片。初步研究了在不同温度（40、50、60、70和80°C）下对大象苹果片施加超声真空能的情况。在60±12°C下可获得最佳结果。干燥样品的DPPH自由基清除活性，总酚含量和总黄酮含量分别为50±2μmolTE / g，31±1 mg GAE / g和12±1 mg槲皮素/ g。将超声真空干燥（UVD）的效果与使用真空干燥（VD）和托盘干燥（TD）干燥的切片进行比较。干燥象苹果片至最终水分约为8.5±1％（db）所需的时间对于TD，VD和UVD分别为930、870和690分钟。使用9个薄层干燥模型测试了大象苹果片的干燥动力学。²（0.9971-0.9989）和低χ ²（0.00039-0.00056）值。UVD可能是用于干燥象形苹果切片的有用的非热技术，它可以加快干燥动力学并改善最终产品的质量。