Drying effects on Camu‐camu residue: An approach of mathematical modeling, thermodynamic properties, and color evaluation in order to obtain a natural food dye

Abstract

The present study evaluated the drying of camu-camu pomace (reducing waste generation), and a mathematical model is proposed for drying at four different temperatures (60, 80, 100, and 120°C), and 1 m/s airflow. The thin-layer model that best fitted the experimental data was by Midilli, compared to ten other models. The evaluation method used the coefficient of determination (R2), RMSE (root mean square), and X2 (Chi-square), wherein the coefficient of determination remained >0.90. The activation energy calculated in the present study was 10.82 kJ mol−1, and effective diffusion coefficient D0 = 0.0012 (m2 s−1). Considering colorimetric parameters and the time of water mass loss, the temperature of 80°C is appropriate to produce a good powder. Thus, the drying of camu-camu pomace is an alternative to obtain a natural (red-purple) food dye. Novelty impact statement To our knowledge, the present study is a pioneer on the grounds that it presents the mathematical modeling data of the residue at high temperature, and also the obtention of camu-camu powder as natural dye. Considering the perishability of fresh residues, drying is one of the most feasible technological processes for the food industry, also to obtain natural dyes, highlighting to the natural powders. The modeling of drying curves provides an understanding as regards the physical and thermodynamic indices relevant to the heat and mass transfer process of the sample. So, this information is very important and might help to improve the performance of future analyses.