Dehydration of pequi slices (Caryocar brasiliense Camb.) by infrared: Modeling and effective diffusion coefficient

Abstract

AbstractOne of the ways to enable and preserve the quality of an agricultural product is through its dehydration. Drying by infrared radiation has been gaining great attention from the industry, as it promotes better heating uniformity, conferring better quality characteristics when compared to traditional drying methods. Thus, this study aimed to model the drying kinetics of pequi slices, subjected to drying by infrared radiation. Pequi fruits (Caryocar brasiliense Camb.), harvested manually in different stages of maturation (green and ripe), with initial moisture contents of 1.06 and 2.20 kga kgdm−1, were used for the green and ripe fruits, respectively. The fruits were peeled and cut into slices approximately 40 mm long and 2 mm thick. The slices were subjected to the infrared drying process under the temperatures of 55, 65, 75, 85, and 95°C. During drying, the effective diffusion coefficient was evaluated. Among the mathematical models that were adjusted to the experimental data, the modified Henderson and Pabis model satisfactorily described the period of decreasing drying rate of pequi slices. During the drying process, the diffusion coefficient increased linearly with temperature, ranging from 8.15 × 10−10 to 1.76 × 10−9 m2 s−1 for green pequi slices and 1.01 × 10−9 to 2.04 × 10−9 m2 s−1 for ripe pequi slices.Practical applicationsPequi fruit is characterized as an important native product of the Brazilian Cerrado, being a considerable source of income for the producing regions. Due to seasonality, there is a need to store the fruits. Thus, this study aims to help researchers and the pequi processing industry, proposing an alternative for marketing in the dehydrated fruit form, by infrared drying, to enable and preserve the quality of the product.