CHANGES IN PHYSICO‐CHEMICAL, THERMAL, COOKING AND TEXTURAL PROPERTIES OF RICE DURING AGING

Studies were undertaken to investigate the effect of aging on the physico‐chemical, thermal, cooking and textural properties of milled rice obtained from two rice cultivars (Basmati‐370 and Sharbati). The physicochemical properties like amylose content, liquification number decreased while the free fatty acid content increased with aging. Basmati‐370 milled rice had higher cooking time and elongation ratio which subsequently increased with aging in both the cultivars. Water uptake and gruel solids loss also decreased significantly with the aging of the milled rice from both the cultivars. Sharbati milled rice showed higher transition temperatures, enthalpy of gelatinization and peak height index than Basmati‐370 rice cultivar when determined by Differential Scanning Calorimeter. All these thermal parameters decreased with the aging of milled rice from both the cultivars. Textural properties such as packability, hardness, cohesiveness, extrudability and chewiness of cooked rice were measured using Instron Universal Testing Machine by back extrusion test. Basmati‐370 cooked rice had higher packability, hardness, cohesiveness, extrudability and chewiness value as compared to Sharbati cooked rice. The values for all textural parameters in both the cultivars increased during aging, however, the increases were greater in Basmati‐370 rice.