OSMO-Microwave Drying of Pineapple (Ananas comosus) Slices: Mass Transfer Kinetics and Product Quality Characterization

This present research aimed to investigate the effect of slice thickness and concentration of the osmotic solution on mass transfer kinetics, the color profile of osmotically dehydrated pineapple slices, and product quality characteristics of osmotically dehydrated microwave-dried (ODMWD) products. Three slice thicknesses (0.5, 1, and 1.5 cm) and three concentrations of osmotic solution (40, 50, and 60 °Brix) were used. The mass transfer kinetics (moisture reduction behaviour, weight loss, solid gain), physicochemical properties (color, TSS, pH, titratable acidity, vitamin C, and total sugar), and total phenolic content of pineapple slices were analyzed. During osmotic dehydration, the moisture reduction behaviour of 0.5 cm slices was faster in all osmotic solutions, whereas water loss and solid gain were higher for all slices treated with 60 °Brix. Both slice thickness and concentration of the solution significantly affected the color of OD pineapple slices. For ODMWD products, total soluble solids (TSS), pH, ascorbic acid content, total sugar, and total phenolic content increased for all slice thicknesses with an increase in osmotic solution concentration, whereas titratable acidity exhibited the opposite result. The rehydration ratio was higher in 0.5 cm slices for all solution concentrations. According to the finding, pineapple fruits can be dehydrated by using 60 °Brix solution concentration with 0.5 cm slices for making dehydrated pineapple fruit, and osmotic dehydration followed by microwave drying of pineapple fruit could be used for value-added processing products.