Mathematical modeling of the drying kinetics of endive leaves

Abstract

ABSTRACT Endive is a vegetable traditionally eaten as a raw or cooked salad. It is a source of important nutritional compounds and one of the procedures for its industrialization is drying, which increases its shelf life, preserves the nutrients and reduces losses due to microorganisms. This research evaluated the drying kinetic of endive leaves at different temperatures and adjusted the experimental data according to mathematical models. The experimental design was completely randomized in triplicate, with each sample unit being a perforated aluminum tray containing about 100 g fresh leaves. The endive leaves were dried in an oven at 50, 60, 70 and 80°C. The mathematical models were adjusted according to the experimental data; non-linear regression analysis was performed by Gauss-Newton and Quasi-Newton methods. In all conditions, the mathematical models that best fitted the drying kinetics of the endive leaves were Midilli, Logarithmic and Valcam. The Logarithmic model, under these drying conditions, can be accurately described as suitable for predicting and simulating the drying kinetic of endive leaves, as it showed the best results in the statistical parameters evaluated.