The impact of using polyols as osmotic agents on mass exchange during osmotic dehydration and their content in osmodehydrated and dried apples

Abstract

The purpose of this study was to evaluate the possibility of using polyols (erythritol, xylitol, and maltitol) as alternatives to sucrose commonly used for osmotic dehydration (OD) of apples and to determine their content in osmotically dehydrated and dried fruit. For comparison, apples were also dehydrated in a sucrose solution. The content of sugars (sucrose, fructose, and glucose) was determined as well. Osmotic dehydration was examined at a temperature of 40 °C in time ranges between 15 and 360 min, and also 1440 min. The polyol solutions were equally or significantly more effective in the OD of apples compared to the sucrose solution. Regardless of the type of osmotic solution, the water loss of apples was from 2 to 10 times greater than solid gain. The color of fruit dehydrated in sucrose and xylitol solutions was characterized by the smallest total color difference (7.9–10.5) compared with the fresh apple tissue. Osmotic dehydration of apples in polyol solutions resulted in the transfer of these substances to fruit tissue. Erythritol was the most effective osmotic agent. The use of polyols for the OD of fruit at the pretreatment stage and the appropriate drying method can be used to create products with high qualities among others due to the lack of added sugars. The use of hybrid drying after the osmotic treatment is a good alternative to the freeze-drying process.