POTENTIAL ANTIOXIDANT AND CHELATING ACTIVITY OF PROTEIN FRACTIONS FROM COMMON BEANS (Phaseolus vulgaris)

In this work, we evaluated antioxidant and metal chelating activities of common bean proteins. Protein fractions were produced by using extraction with organic (method 1) or aqueous (method 2) solvents. Results evidenced that the amount of proteins extracted through method 2 was higher than method 1, probably due the chemical difference between solvents. The antioxidant activity of hard-to-cook beans were lower than easy-to-cook beans by both tested methods, DPPH and FRAP. However, after extrusion it was observed a significant increase in the antioxidant activity determined by DPPH and FRAP for all protein fractions. Metal chelating results evidenced that thermal processing was able to improve the Fe and Cu-chelating activity of common bean proteins. In this context, the presence of antioxidant and chelating activity in the native bean proteins allows to suggest its use as functional ingredient in food formulations in order to prevent oxidative stress related diseases.