Chemical Composition, Antioxidant Capacity, and Sensory Quality of Dried Sour Cherry Fruits pre-Dehydrated in Fruit Concentrates

The aim of this study was to determine the effect of combined drying methods by osmotic dehydration (OD) using several fruit concentrates (apple, blackcurrant, chokeberry, sour cherry, raspberry, quince, flowering quince) or sucrose solution, before combined drying involving convective drying (CD) and vacuum-microwave finish drying (VMFD), on the quality parameters (phenolic compounds, antioxidant activity, color, and other chemical parameters (titratable acidity, pH, dry matter, and water activity)) of dried sour cherry (DSC). OD in some concentrates resulted in enriching the DSC in polyphenols (from 6.4 to 22.4 % OD in sour cherry and chokeberry, respectively), especially in polymeric procyanidins (up to 1.5 times OD in the chokeberry concentrate), but it also reduced the content of anthocyanins (from 10.14 to 65.07 % OD in blackcurrant and sucrose solution, respectively). OD pre-treatment stimulated also the antioxidant activity and other chemical parameters of the DSC. The study revealed that DSC osmo-dehydrated prior to combined drying approach allowed for obtaining attractive final products.