Effect of edible surface coatings followed by dehydration on some quality attributes and antioxidants content of raw and blanched tomato slices

Abstract

Changes in quality attributes and antioxidants content of tomato slices coated with gum Arabic at different concentrations then sun- or air-dried were investigated. Drying increased the dry matter content and the rehydration ratio with increase in gum Arabic concentrations. The water activity was fluctuated. Slices coated with 10% gum Arabic and air-dried had a maximum dry matter content (84.87%), a minimum water activity value (0.27) and a higher rehydration ratio (4.69), compared to uncoated slices. Drying of slices before and after coating had no significant (p≤0.05) effect on the pH. Coating of the slices followed by drying had no effect on the total soluble solids content. Blanched slices coated with 10% gum Arabic and sun-dried had a lower browning index value (0.029). Dried uncoated slices were darker than coated slices. Surface coating alleviates the effect of heat on the ascorbic acid, total phenolics, and flavonoid contents.