Drying Kinetics, Quality Characteristics and Mathematical Modeling of Circular Shaped Cassava Slices: Effect of Varieties, Thicknesses, and Drying Methods

ABSTRACT Drying is a crucial unit operation in cassava flour processing, as the product quality is largely determined by the drying method employed. The main objective of this study was to optimize the variety, slice thickness, and drying method to maintain the quality of cassava slices for producing high quality cassava flour (HQCF), which serves as a key ingredient in developing gluten free food products. Drying experiments were conducted using three drying methods (open sun, solar, and convective hot air drying), three slice thicknesses (1.5, 2.5, and 3.5 mm), and three varieties (Sree Athulya, Sree Suvarna, and M4). The moisture content of the dried slices ranged from 7.70% to 10.75% (dry basis). Among the tested conditions, convective hot air drying of 1.5 mm slices resulted in the highest drying rate (0.24 g•g −1 •min −1 ) and shortest drying time (180 min), irrespective of variety. Cassava slices of 1.5 mm thickness dried under solar drying retained the most desirable quality attributes, including higher starch content and whiteness. The Sree Athulya variety exhibited the highest starch content (76.27% ± 0.82% d.b.) and a whiteness index of 87.43. Statistical analysis revealed that the interaction among drying method, slice thickness, and variety had a highly significant effect ( p ≤ 0.01) on the quality attributes of cassava slices. Solar drying of 1.5 mm thick slices across all the varieties was identified as the optimal condition for producing high quality cassava flour (HQCF). Seven thin layer drying models were applied to describe the drying kinetics of cassava slices. The Page model provided the best fit, as indicated by its high R 2 and low RMSE and χ 2 values, confirming its suitability for characterizing thin‐layer drying behavior under varying conditions. Thus, solar drying is an efficient method for producing high quality cassava flour from thin (1.5 mm) cassava slices, suitable for developing gluten free food products.