During rice processing, bran rice is obtained as a coproduct which presents a high nutricional value and functional properties such as antioxidant, antihipertensive, hipoalergenic proteins source, decrease in blood cholesterol, among others. This coproduct presents great protein content including albumins, globulins, glutelins and prolamins in greater proportion. Bran rice proteins present functional properties that have been poorly studied.
The objective of this work was to obtain information about bran rice proteins and its fractions as to their antioxidant properties.
Bran rice was provided by Saman S.A. which was defatted by Soxhlet method using hexane as the extraction solvent. Defatted bran rice was submited to water extraction obtaining soluble protein fraction and was separated by molecular exclution cromatography with Sephadex-G75 column (phosphate buffer 10 mM pH 7.4 as the elution buffer) obtaining low and high molecular weight fractions. Characterization of soluble extract and fractions was performed by tricine gel electrophoresis and proteic content was also determined. In addition, soluble extract and fractions antioxidant capacity was determined by ABTS and ORAC methods. The results indicated that the high molecular weight fraction had better antioxidant capacity (p≤0.05), followed by the low molecular weight fraction and soluble extract to the same extent, in both methods.