Antioxidant Activity of Methanolic Extracts of Various Oilseed Protein Ingredients

Abstract

ABSTRACT Antioxidant activity (AA) of methanolic extracts of defatted flours, concentrates, and isolates produced from glandless cottonseed, peanut, and soybean was determined against linoleate oxidation catalyzed by metmyoglobin (MetMb), Fe ++ ‐EDTA (1:l molar ratio) and fresh beef homogenates and against autoxidation of safflower oil. Total phenolic content of the extracts was also determined. Methanolic extracts of glandless cottonseed protein ingredients showed uniquely and consistently higher AA than those of peanut and soy protein ingredients. Total phenolic content was also markedly higher for the cottonseed protein extracts. Methanol‐soluble AA was significantly correlated with total phenolic content for the extracts of defatted flours and concentrates but not for the extracts of isolates. The comparative methanol‐soluble AA values of these oilseed protein ingredients were indicative of their antioxidation potential in cooked meat products.