Moisture, texture and sensory changes in pistachio nuts as affected by roasting temperature and storage time

In this work the effect of roasting temperature and storage on the moisture content، texture and sensory attributes of pistachio nuts were investigated. Pistachio nuts were salted and then roasted using conventional method at 90، 120، and 150 ˚C for 30 min. The changes occurred in the moisture content، textural properties (hardness and fracture force)، and sensory attributes (firmness and total acceptance) of salted roasted pistachio nuts were determined during 3 months of storage. The textural properties were correlated with sensory attributes. Multiple linear regression was used to predict the effects of roasting temperature and storage time on textural properties. Hardness and fracture force as well as firmness increased across the storage time for all roasted pistachio nuts. Furthermore، during the storage، the moisture content of roasted pistachio nuts increased. By increasing the roasting temperature، moisture content، hardness and fracture force were significantly decreased. In addition، using high temperature of roasting led to less firmness. Higher total acceptance obtained for samples roasted at temperature of 120 ˚C. The results indicated that the correlation between instrumental and sensory properties was significant.