Effect of osmotic agents and ultasonication on osmo‐convective drying of sweet lime (Citrus limetta) peel

Abstract

AbstractThe study was aimed to evaluate the effect of different osmotic agents (sucrose, maltodextrins, and stevia, 50° brix conc.), immersion time (2–8 hr), and ultrasonication treatment (33 KHz, for 2, 5 and 10 min) on water loss, solid gain, weight reduction and subsequent air drying (45°C) behaviour of sweet lime peel. Irrespective of immersion time, the average water loss, solid gain, and weight reduction were observed to be maximum with sucrose as osmotic agent followed by maltodextrins and stevia, respectively. There was only a slight increase in the values of water loss, solid gain, and weight reduction during the ultrasonic‐assisted osmotic dehydration. Sucrose was observed to be the best osmotic agent for osmo‐convective drying of the sweet lime peel. The ultrasound pretreated (10 min, 33 kHz) and sucrose‐osmosed sweet lime peel when subjected to air‐drying, the moisture content was decreased from 28.70 to 1.91%. The values of R2, adjusted R2, and RMSE and residuals analysis indicated that Page model satisfactorily described the drying behavior of sweet lime peel.Practical applicationsPeels are the main by‐products of sweet lime processing for juice manufacturing. The fruit waste is very rich in pectin and potentially valuable bioactive compounds including antioxidants. The findings of this study may prove instrumental in designing the osmo‐convective drying technology for the sweet lime peel. Since OD can contribute to the retention of useful bioactive compounds and the dried sweet lime peel in its powder form has high concentration of pectin, it can find useful applications in the health industry and food industry especially in processed products such as jams, jellies, or bakery products like biscuit and bread with added functionality and nutraceutical properties. The utilization of osmotically dried sweet lime peel will not only add to the income of sweet lime fruit processors but also provide an avenue for its waste disposal also.