Effect Of Processing On Nutritional Composition, Phytate And Functional Properties Of Rice (Oryza sativa L) Flour

Abstract

Physico-chemical properties of dehusked rice (Oryza sativa) and its flours of raw, cooked and soaked grains were analyzed for proximate composition, valuable mineral, phytate contents and functional properties. The physico-chemical properties of the raw sample varied as follows: Density (0.58g/ml), cooking time (45 min.) hydration capacity, hydration index, swelling capacity and swelling index were low; dispersability in both cold and hot water was good. The proximate composition ranged as follows: moisture (10.54-19.27g/100g): crude fibre (1.05-1.65g/100g); carbohydrate (71.95-85.45g/100g); ash (2.0-2.3g/100g) and energy (361-402.40Kcal; 1531.50-1706.45KJ). Raw sample contained higher amounts of minerals than cooked and soaked samples. In all the minerals recorded potassium was the most abundant (375.75-400.00mg/100g). The levels of phytate and phytate phosphorous were high and the samples had between 11.08 and 19.33% of the total phosphorus linked to phytate. All the samples had good water absorption capacity, least gelation capacity, oil absorption capacity, foaming capacity, emulsion stability and foaming stability which collapsed within 60 min, but cooked and soaked samples were significantly reduced (P<0.05) during processing.

Key words: Oryza sativa, nutritional composition, phytate, functional properties.

Nigerian Food Journal Vol.22 2004: 97-104