Evaluation of the drying kinetics, energy consumption and physicochemical properties of Golden delicious apple powders by mixing carrier agents

Abstract In this study, the effects of carrier agents and their usage methods on the drying rate, moisture content, effective moisture diffusion, energy consumption, color, density, Carr ( CI ) and Hausner ( HR ) index values of Golden delicious variety apple powder produced by convective drying method at 60 °C and 80 °C were compared. The effects of maltodextrin (M), sorbitol (S) and lactose (L) carrier agents and their M + S, M + L, S + L and M + S + L usage methods in powder production were determined. In the drying processes, purees were dried from an average of 4.77 ± 0.30 g moisture/g dry matter to 0.005 ± 0.0001 moisture/dry matter. It was found that the average drying rates of the samples varied between 6.77 × 10 −3 and 1.44 × 10 −2 g moisture/g dry matter.min. The effective moisture diffusion values were determined to vary between 2.31 and 4.91 × 10 −6 m 2 /s. The average specific moisture absorption ratio ( SMER ) values of the drying processes were determined to vary between 0.0027 and 0.0045 kg/kWh and the specific energy consumption ( SEC ) values were determined to vary between 220.89 and 393.22 kWh/kg. The tapped density values of the powder samples varied between 0.75 and 1.09 g/cm 3 and the bulk density values between 0.67 and 0.82 g/cm 3 . The CI values of apple powders were determined between 1.35 and 38.96% and the HR values were determined between 1.01 and 1.69. The powder samples preserved the L , a and C color values of fresh significantly ( p < 0.05 ). The powders produced under 60 °C-Sorbitol, 60 °C-Lactose and 80 °C-Maltose conditions preserved the b color value of freshness significantly ( p < 0.05 ).