Drying kinetics of Talinum triangulare (Jacq.) Willd leaves and physicochemical assessment of flour

Abstract

Talinum triangulare (Jacq.) Willd (Talinaceae) is a plant cultivated in Africa, Asia, and Latin America for medicinal and food purposes. This study aimed to assess the drying kinetics of T. triangulare leaves under different temperatures and the physicochemical characteristics of flour produced. Leaves were dried to constant weight in an oven at temperatures of 50, 60, 70 and 80 °C. Drying results were adjusted to mathematical models used to represent the drying of agricultural products. After drying, leaves were ground and the flour was analyzed for mineral and centesimal composition and scanning electron microscopy and absorption spectroscopy in the infrared region were performed. Page’s model was the most appropriate for predicting the leaf drying phenomenon. The times required for drying were 32, 10, 7 and 6 hours at temperatures of 50, 60, 70 and 80 °C, respectively. Contents of N, Mg, and Cu in the flour samples were influenced by increasing drying temperature. Other variables of mineral, centesimal and structural composition were did not change. Due to the nutrient contents present in the leaves of T. triangulare, the flour produced can be used in new products.