Characterization of physicochemical, packing and microstructural properties of beet, blueberry, carrot and cranberry powders: The effect of drying methods

Physicochemical, packing and microstructural properties of beet, blueberry, carrot, and cranberry powders produced by hot-air drying (HAD), freeze drying (FD), and a film drying method (InfriDri® Process (IFD)) were evaluated. Higher bulk and tapped densities were recorded in the IFD powders than other powders. The IFD powders had a lower Hausner ratio and compressibility index, a higher wettability index, and were less hygroscopic compared to other powders. The IFD powders had a smooth and flaky appearance while other powders exhibited a more irregular and porous morphology. Total phenolic content (TPC) of the IFD beet and carrot powders was 20.95% and 30.43% higher than that produced by HAD, and 3.42% and 7.96% higher than those from FD, respectively. Similarly, the beet and carrot powders from IFD exhibited an antioxidant activity 21.45% and 11.52% higher than that from the HAD method, and 14.84% and 14.43% higher than the FD counterparts, respectively.