Evaluation of physicochemical properties of dried Damavand’s apple slices under the effect of grape pomace extract

Apple is one of the most valuable fruits which is produced and consumed throughout Iran. Fruit processing especially production of dried slices can be considered as a way to increase the value of apples and to prevent wastes. Producing apple slices with proper color and texture has always been one of the goals of producers in this field. In recent years, use of plant extracts has been the interest of many researchers in order to increase the shelf-life of agricultural products. In this study, the effect of grape pomace extracts (0، 100، 200، 300 and 400 ppm) on the phenolic content, antioxidant activity and color of apple slices dried at 47°C in Industrial dryer, 50°C and 60°C in oven were investigated. The results showed, the highest DPPH radical scavenging activity (85.97%), Fe reducing power (1.87 absorbance at wavelength of 700 nm) and phenolic content (245/87 mg of gallic acid equivalents in 100 g of dry matter) were achieved using 400 ppm concentration of grape pomace extracts. Also, the highest sensory score of dried apple slices were achieved at 300 ppm concentration of grape pomace extracts. In general, the results of this study indicated that the effect of Grape pomace extracts on the quality of apple dried slices was significantly positive. Concentration of 300 ppm of grape pulp extract has positive effect on the amount of phenolic complex and antioxidant properties of apple slices and its does not affect its taste.