Effect of Hot-Air Convective Drying on Activity Retention of Amylase and Invertase in Dried Mango of Varieties Sindri, SB Chaunsa, and Tommy Atkins

Recently, fruit-drying industries are showing great interest in producing dry fruits that preserve a high enzyme content. Therefore, this study aimed to investigate the effect of hot-air convective drying on activity retention of amylase and invertase in dried mango of varieties Sindri, Samar Bahisht (SB) Chaunsa, and Tommy Atkins. Convection drying was conducted under over-flow mode at five temperatures (40, 50, 60, 70, and 80 °C), two air velocities (1.0 and 1.4 m s−1), and constant specific humidity of 10 g kg−1 dry air. The enzymatic degradation data were fitted to the first-order reaction kinetics model, in which the temperature dependence of the rate constant is modelled by the Arrhenius-type relationship. Results showed that the maximum amylase and invertase activity for dried mango of all three varieties was best preserved in samples dried at a temperature of 80 °C and an air velocity of 1.4 m s−1. In contrast, a lower drying temperature and an air velocity of 1.0 m s−1 contributed to a significant decrease (p < 0.05). Exploration of different temperatures and air velocities to save amylase and invertase in dried mango is useful from an industrial point of view, as mango can be a natural dietary source of digestive enzymes to improve digestion.