HYDRATION, SWELLING AND SOLUBILITY BEHAVIOR OF RICE IN RELATION TO OTHER PHYSICOCHEMICAL PROPERTIES

Water uptake at 90 degrees C and above in 16 rice cultivars, represent ing eight cooking-quality types, showed positive correlation (P < 0.00 1) with the surface area of the grain, while at 60 degrees C it was ne gatively related to amylose (P < 0.01), and gelatinisation temperature (P < 0.001), and positively to equilibrium moisture content on soakin g (P < 0.001). The swelling and solubility curves for all varieties sh owed a two-stage swelling pattern. Swelling at 60 degrees C was positi vely correlated (P < 0.001) with water uptake at 60 and 70 degrees C, while swelling at 70 degrees C, and solubility at 60 and 70 degrees C, showed highly negative correlation (P < 0.001 and P < 0.01, respectiv ely) with water uptake at high temperatures. Waxy rices showed distinc t differences from non-waxy rices in their hydration, swelling and sol ubility behaviour. They swelled more but solubilised less than the non -waxy rices at 96 degrees C.