Modeling of solar drying behavior and quality evaluation of sun-dried wood apple (Limonia acidissima) pulp

Abstract

Wood apple (Limonia acidissima L.), an underutilized indigenous fruit rich in bioactive compounds, was processed into a stable powder through solar drying under Bundelkhand’s climatic conditions. The study aimed to evaluate the drying kinetics, physico-chemical composition, antioxidant properties, and functional quality of the sun-dried product. The pulp was dried in a solar dryer, and moisture loss was recorded at regular intervals. Thin-layer drying models were fitted to the experimental data, with the Page model showing superior fit (RMSE = 0.017) compared to the Newton model (RMSE = 0.030). The resulting powder exhibited high carbohydrate content (86.45%), moderate protein (4.13%), and low fat (1.34%), with moisture reduced to 6.77%, ensuring storage stability. Total phenolics (30.67 mg GAE/g) and ascorbic acid (10.42 mg/100 g) levels confirmed the product’s antioxidant potential. FTIR analysis revealed characteristic peaks associated with hydroxyl, carboxyl, and aromatic functional groups, validating the presence of polyphenols, organic acids, and carbohydrates. Sensory evaluation indicated high consumer acceptability, with scores above 7.0 for all attributes. These findings demonstrate that solar drying is an effective, low-cost method for converting wood apple pulp into a value-added functional ingredient, suitable for use in nutraceuticals and health-oriented food products.