Moisture diffusion by the fractional-time model in convective drying with ultrasound-ethanol pretreatment of banana slices

Abstract

Innovative drying pretreatments play an essential role in preserving food and reducing drying energy consumption. The aim of this study was, therefore, to investigate the effect of drying pretreatments with ethanol (EH) and ultrasound (UA) on the drying kinetics and moisture diffusion through an anomalous solution by the fractional time, as well as to evaluate the physical, bioactive compounds and antioxidant properties of banana slices. The results indicated that Page's model analyzed the anomalous calculus approach for emerging drying techniques with the appropriate goodness of fit. The anomalous diffusivity approach described the experimental data well and provided new insights into the structure of food material. The new approach also showed that drying pretreatments promote convective drying, reduce drying time by up to 31% and save energy by 19%. Analytical results showed that banana slices pretreated with EH + UA had higher conservation of phenolic compounds and antioxidant activity, as well as an attractive color and high shrinkage. The findings could provide help in the large-scale processing of good-quality dried banana slices.