Interactive effects of soaking duration and drying temperature on the drying kinetics and proximate composition of tiger nuts (Cyperus esculentus L.)
摘要
This study investigated the interactive effects of soaking duration (24, 48, and 72 h) and drying temperature (40, 50, 60, and 70 °C) on the drying kinetics and proximate composition of tiger nuts (Cyperus esculentus L.). Fresh tubers were subjected to factorial treatments under a completely randomized design. Drying data were fitted to thin-layer models to describe moisture transfer behavior, while proximate composition was determined using standard AOAC methods. Drying occurred exclusively in the falling-rate period, with effective moisture diffusivity increasing and activation energy decreasing under higher temperatures and extended soaking, respectively. Among the models evaluated, the Page model provided the best fit for predicting drying behaviour. Proximate analysis revealed significant (p < 0.05) leaching of ash, fiber, and protein with prolonged soaking, while elevated drying temperatures markedly reduced protein content. The optimal balance between drying efficiency and nutrient retention was achieved with a 48 h soaking pretreatment followed by drying at 50 °C. These findings provide a practical, evidence-based protocol for producing high-nutrient tiger nut flour for functional food applications.