Drying effect on physical and physicochemical properties and bioactive compounds of kiwifruit powder

This study aimed to evaluate the effect of convective drying at different temperatures on the physical and chemical properties of kiwifruit powder. Circular kiwi slices were cut with thickness of 5.0 mm and subjected to different drying air temperatures (50, 60, 70 and 80 ºC). After drying, the slices were ground to obtain the powder and characterized for the physical parameters, physicochemical parameters and bioactive compounds. The powders were characterized for physical and physicochemical attributes and bioactive compounds. The experimental design was completely randomized, with three replicates, and the data were subjected to analysis of variance by F test and to Tukey test at 0.05 probability level. Kiwifruit powders obtained by convective drying at 50, 60, 70 and 80 ºC were classified as non-hygroscopic, showing good flowability and low cohesiveness. Kiwifruit powders obtained at temperatures of 70 and 80 ºC had lower moisture content and water activity, with predominance of yellow intensity over red intensity, which influenced their final color according to the drying air temperature. Powders obtained at the four drying temperatures showed significant amounts of bioactive compounds; thus, they can be consumed in powder and used in the preparation of food products. However, samples dehydrated at temperature of 70 ºC had higher contents of phenolic compounds compared to the others.