Characterization and antioxidant evaluation of phenolic compounds extracted from the protein concentrate and protein isolate produced from pawpaw (Carica papaya Linn.) seeds

Abstract

In this study, the qualitative and quantitative analysis of the absolute (100%) and aqueous (80%) methanolic extract of Carica papaya Linn processed seed flour samples in terms of their antioxidant properties and their phenolic compounds was investigated. The antioxidant properties were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power, and metal chelating assay methods. The protein isolate exhibited higher radical scavenging activity power as compared to other samples. Ferulic acid, caffeic acid, p-coumaric acid, kaempferol-3-glucoside, p-hydroxybenzoic acid, and quercetin-3-galactoside were phenolic compounds isolated with ferulic acid as high as 0.62 mg/DWg. Carica papaya seed isolates and concentrate demonstrated potent antioxidant activity and could be of nutraceutical importance in the pharmaceutical and food industry.