MATHEMATICAL MODELING OF MOISTURE SORPTION CHARACTERISTICS OF DRIED TURMERIC (Curcuma longa L.) POWDER

Abstract

The mathematical modeling of moisture sorption characteristics of dried turmeric (Curcuma longa L) powder was carried out to fit the sorption data of different sorption models. The dried turmeric powder sample of initial moisture content 8.74% (wb)was dried in the cabinet dryer and EMC was determined by static gravimetric technique at temperatures: 20±1°C, 30±1°C and 40±1°C maintaining the aw ranging from 0.16-0.92. Results from the experimental analysis revealed that the sorption isotherms were of sigmoid shaped type II pattern as classified by Brunauer et al. (1998). Statistical analysis showed that BET model gave the best fitting followed by Caurie and Hasley model over the entire range of experimental temperatures with the higher value of R2 ranging from 0.93-0.97 and lower values of χ2(0.00046-0.0209), RMSE (0.026-0.156) and SSE (0.00140-0.138) compared with other models. The monolayer moisture content decreased with increasing temperature. Such data represents a useful tool for choose appropriate storage condition and preservation techniques for the dried turmeric powder.