MOISTURE DESORPTION CHARACTERISTICS OF CASHEW KERNELS

摘要

Desorption isotherm of cashew whole kernels were determined at 60, 70 and 80°C using water activity analyzer (Aqua-lab model). Non-linear curve fitting technique is used to validate seven moisture sorption models viz., Oswin, Smith, Halsey, Henderson, Modified Henderson, Modified Oswin and Chung and Pfost considering error parameters randomness of residuals (e_i), standard error of estimate (E_s) and mean relative percentage deviation (E_m). Desorption isotherms were of Sigmoid shape, typical for many biological products. Curve fitting agreement of observed data for selected isotherm models revealed that Smith equation is the best fit to describe desorption characteristics of cashew whole kernels. The parameter values 'a' and 'b' of Smith equationare found to be 6.740 and 12.945 respectively. Temperature has a significant effect on desorption isotherms. The equilibrium moisture content of cashew kernels at constant water activity decreased with increasing temperature.