Effect of ultrasound-assisted osmotic dehydration pretreatment on drying ofpineapple core

This research aimed to evaluate the effects of ultrasound-assisted osmotic dehydration (UAOD) on the drying of pineapple core slices. This study compared conventional osmotic dehydration (OD) utilizing sucrose as the osmotic agent, at varying volumes of 10, 30, and 50 mL, as well as immersion times of 2, 31, and 60 mins. The OD process served as a control with no sonication treatment. Response variables including water loss, solid gain, hardness change, and stickiness change were measured. The optimal osmotic pretreatment conditions were determined after assessing the effect of sucrose solution volume and immersion time on response variables. The effect of the osmotic pretreatment conditions on the drying time and water diffusivity was also evaluated. The results showed that water loss increased with treatment time, while solid gain and texture exhibited a decline. The optimal conditions identified were a sucrose solution volume of 50 mL with a 2-min immersion time for OD and 37.76 mins for UOAD. Results indicated that UAOD significantly decreased drying time by 23% and allowed moisture content to reach as low as 15%, while OD could not reach moisture content below 30% without sonication. These findings suggested that UAOD can improve both the quality and drying efficiency in pineapple processing, while also positioning pineapple core as a valuable food product and improving energy efficiency in the pineapple processing industry.