The effect of temperature, time and air velocity of roasting on textural properties of pistachio kernels

Roasting is the common shape of pistachio nuts processing and the purpose of this process is to increase the total acceptability of products. The aim of this study was the effects of hot air roasting temperatures (90, 120 and 150°C), times (20, 35 and 50 min) and air velocities (0.5, 1.5 and 2.5 m/s) on textural attributes (fracture force, hardness, apparent modulus of elasticity and compression energy) and stress relaxation behavior of pistachio kernels. Increasing the temperature of roasting decreased the fracture force (from 71.95 N to 43.10 N), hardness (from 78.15 N to 47.22 N) and compression energy (from 235.61 J to 130.80 J) of pistachio kernels (P0.05). Increasing the temperature, time and air velocity of roasting decreased the apparent modulus of elasticity (P