中文摘要：

超声波的空化效应及机械效应可有效增强脱水过程中物料内外的质量传递速率,因此超声波技术可用于果蔬渗透脱水的强化,而超声渗透脱水又常作为其他干燥方式的预处理以提高脱水速率。本研究以砀山梨梨片为实验材料,进行超声波渗透脱水预处理联合热风干燥研究。结果表明：提高超声功率及渗透液糖度可显著增加失重率;与直接热风干燥相比,单一的渗透脱水预处理延长总脱水时间约30~60 min;而超声渗透脱水预处理可缩短热风干燥的干燥时间40~120 min,并提高有效水分扩散系数11%~56%。因此,在热风干燥前进行超声渗透脱水预处理,可有效缩短总工艺时间,提高干燥效率。

英文摘要：

In this study, fresh-cut slices of ‘Dangshan’ pear were pretreated by means of ultrasonic-assisted osmotic dehydration before hot-air drying for the purpose of obtaining enhanced dehydration rate. The influences of operational parameters including ultrasonic power and osmosis concentration on weight reduction ratio, drying time and effective moisture diffusivity were examined. The results showed that increasing the ultrasonic power and sugar concentration in the osmotic solution signifi cantly improved weight reduction ratio. Compared with direct hot air drying, the total dehydration time for pear slices pretreated by osmotic dehydration without ultrasonic treatment was prolonged by 30 60 min, but shortened by 40 120 min for those pretreated by ultrasonic-assisted osmotic dehydration, simultaneously with an increase in effective moisture diffusivity coefficient of 11% 56%. Therefore, it is concluded that the use of ultrasonic-assisted osmotic dehydration as a pretreatment procedure before hot air drying can signifi cantly shorten the total process time and subsequently improve the drying eff iciency.