Evaluation of various drying approaches on the physicochemical properties, rehydration kinetics, mathematical modeling and quality of tiger nut (Cyperus esculentum)

Abstract

In this study, the quality and physicochemical properties as well as rehydration kinetics of dried tiger nuts were examined in relation to four different drying techniques. Tiger nuts were dried using the infrared dryer (ID), hot air dryer (HA-D), electric oven dryer (EOD), and sun dryer (SD). Effects of models on the rehydration kinetics of tiger nuts processing (drying) under various drying processes were tested, along with the antioxidation, sensory qualities, total phenolic content (TPC), moisture content (MC), and chromatic aspects of the dried slices. The Weibull model had the highest coefficient of determination (R2) > 0.99, residual sum of squares (RSS), reduced chi-square (2), and root mean square error (RMSE). In terms of chromatic characteristics, antioxidation, DPPH (83.55 mgTE/g db) and TPC (72.28 mg GAE/g db), the ID-tiger nut samples had the highest retention rates with lowest MC (5.67%). The dried samples varied significantly from HA-D, EOD, and SD in terms of their rehydration ratio (RR) and rehydration kinetics (p < 0.05). In conclusion, the appropriateness and prospective industrial wide-scale application of the numerous dehydrating processes were determined for all the qualitative attributes tested in the following order: ID > HA-D > EOD >SD.