Water sorption isotherms of pistachio nuts

Abstract

The adsorption and desorption isotherms of pistachio nuts (kernel and shell) were measured at 15, 25 and 40°C using a gravimetric method. Hysteresis was more pronounced in the shell than in the kernel and reduced as the temperature increased. The isosteric heat of desorption, calculated from the slope of a lnaw vs. 1/T plot, was higher than the isosteric heat of adsorption. The GAB equation gave satisfactory goodness of fit with average percent deviation of less than 5%. ©1996 Academic Press Limited.