Investigation of Drying Kinetics and Powder Product Properties of Dragon Fruit Powders Dried by Microwave Assisted Foam Drying Method

Abstract

In this study, dragon fruit was dried by a microwave-assisted foam drying method and the effect of different microwave powers (350, 460 and 700W) on the drying kinetics and powder product properties were investigated. The properties (foam stability, expansion and density) of the foams obtained by adding egg white to dragon fruit puree were examined. The highest R2 and lowest RMSE and χ2 values of foam dried samples obtained from the Silva models. The effective moisture diffusion coefficient values of the samples (5.93×10-8-1.16×10-7 m2/s) increased due to the increase of microwave power. Activation energy values were calculated as 74.77 W/g. The effects of different microwave powers on moisture, water activity, color and powder product properties of dragon fruit powders dried by foam drying method were determined. In addition, in all conditions where microwave foam drying is performed, dragon fruit powders showed very good flowability and low stickiness.