Microwave-assisted Refractance Window Drying of Beetroot Puree

Abstract

Objective: To develop a microwave-assisted refractance window-drying process for beetroot puree and to study its effect on the physiochemical quality of the powder Methodology: Beetroot puree with a moisture content of 89.01% was dried using combined microwave and refractance window drying (RWD) methods. Microwave (MW) energy was supplied at a power density of 0.57 W/g with a pulsation ratio of 1.5 and continuous supplied (without pulsation). The sample thickness was maintained at 1 and 3 mm. Drying kinetics, Specific energy consumption, and physiochemical quality characteristics were studied. Results and Conclusions: Drying kinetics were studied by fitting at various thin-layer drying models. Page model was found to be the best-fitted model. Total phenolics and flavonoids compounds and antioxidant activity of powdered beetroot were enhanced due to the breakdown of phenolic compounds by microwave. The developed MW-assisted RWD methods enhanced the phytochemical quality and minimized energy consumption.