MODELS FOR PREDICTING SORPTION BEHAVIOR OF GUNA (Citrullus lanatus) SEEDS

The moisture sorption behavior (adsorption and desorption) of guna seeds (shelled and unshelled) was observed under water activity range of 0.147 to 0.981 and temperatures of 10oC, 30oC and 50oC, respectively. The sorption data were subjected to spreadsheet computer plots (Microsoft excel) of equilibrium moisture content versus water activity. Best fit curves were observed to be polynomials of the third order with correlation coefficients (for unshelled seeds) ranging from 0.9854 to 0.9434 for adsorption and 0.9778 to 0.9749 for desorption and percentage root mean square of error (%RMS) ranged from 0.63 to 1.35 and 0.58 to 0.65 for adsorption and desorption, respectively. The curves for the shelled seeds showed correlation coefficients that ranged from 0.9812 to 0.8986 for adsorption and 0.9706 to 0.9065 for desorption, with corresponding %RMS of 0.66 to 2.15 (adsorption) and 0.76 to 1.41 (desorption). In all cases, the correlation coefficient decreased with increasing temperature while %RMS increased with temperature.