Optimization of process parameters for preparation of rice extrudates from short and long Indica rice cultivars milled to varying degree of milling.

Extrusion behavior of extrudates prepared from short (PR113) and long (PUSA1121) Indica rice cultivars milled to 0-8% degree of milling (DOM) extruded at variable extrusion temperature (150-190 °C) and feed moisture (15-19%) was studied. The physico-chemical and functional properties of extrudates prepared from both the cultivars varied significantly with variation in DOM as well as extrusion variables. DOM showed more pronounced effect for all the responses studied for both the cultivars. Expansion, L*, water absorption and overall acceptability increased whereas hardness, water solubility and bulk density decreased with increase in DOM. Extrusion temperature increase led to increase in expansion and water solubility and decreased L*, bulk density and water absorption. Feed moisture showed significant positive effect on hardness and water absorption and negative effect on expansion, L* and water solubility. Formation of amylose-lipid complexes were also observed during extrusion cooking for both the cultivars which showed negative correlation with DOM. Both the cultivars also showed different behavior for these responses at same values of independent variables.