Evaluation of hot-air drying kinetics of prominent cashew (Anacardium occidentale) pomace in Ogbomoso

Abstract

Cashew pomace is a byproduct of the cashew fruit after the extraction of juice from its apple. Therefore, this study assessed drying kinetics of hot air drying using cabinet and solar drying methods on the Cashew Pomace (CP). Ripe cashew apples were sorted, washed and their juice squeezed out to obtain pomace. The pomace was sliced to a thickness of 2 mm and dried in the cabinet (55, 65 and 75 ᵒC) and solar dryers. The drying processes were evaluated for the CP through appropriate modelling considering six thin layer drying models (Newton, Page, Modified Page, Henderson and Pabis, Logarithmic and two-term). Drying kinetics data were fitted into six thin-layer drying models to select the best model based on the highest R2, lowest χ2 and RMSE value. Data were analyzed using Analysis of variance, with mean separation by Duncan’s Multiple Range Test (p<0.05). The considered models had values of R² (coefficient of determination) that ranged from 0.510 to 0.998 and 0.866 to 0.996, and χ² (chi-square) values ranged from 0.001 to 0.225 and 0.002 to 0.124 for the cabinet and solar drying models, respectively. The Deff (effective moisture diffusivity) ranged from 3.716-277.666 x 10-5 m2/s. The Page model was the preferred drying model for pomace amongst the investigated kinetic models, and drying by cabinet produced samples with better industrial potential. Overall, the investigation suggests the potential for sustaining CP to support industrial growth and generate additional income for smallholder farmers