The influence of physical properties of selected plant materials on the process of osmotic dehydration

Abstract

The aim of this study is to examine the influence of selected physical properties of plant materials on the osmotic dehydration process (OD) in salt, sucrose and concentrated chokeberry juice solutions, and to explore the possible relationships between these factors. The study also evaluated the effect of osmotic solutions on the antioxidant capacity of OD samples. The material consisted of 3 cultivars of pumpkin, beetroot, parsley, carrot, celery, radish, black turnip and apple. Concentrated chokeberry juice, sucrose (40 °Brix) and salt (5 g/100 g) were used as osmotic solutions. The process was performed at the temperature of 45 °C for 90 min.The functional relationships between physico-chemical properties of raw material, osmotic solutions, water loss and solid gain and the quality of the osmotically dehydrated products were found. The water loss was higher than the solid gain during osmotic dehydration, regardless of the solution used for the process. For all samples analysed, water activity decreased after the OD process and was the greatest after the application of chokeberry juice concentrate. The solid true density diminished after OD, regardless of the OD solution. A strong influence of the osmotic solution on the antioxidant capacity was noted when chokeberry juice concentrate was used.