Antioxidant activity and qualitative analysis of wheat bran polyphenols purified using HPD 600 macroporous resin

Abstract

Objective: A process was developed for the purification of bran polyphenols from HPD 600 macroporous resin. The purity and antioxidant activity of the extracts were analyzed before and after purification, and the polyphenol fractions in the purified products were characterized. Methods: The bound polyphenols in wheat bran were extracted by alkali hydrolysis, and the dynamic adsorption-desorption conditions of the macroporous resin were optimized by single-factor test to determine the optimal purification process. The antioxidant activity fraction was determined by ABTS and DPPH radical scavenging rate. The characterization of the polyphenol fraction in the purified product was completed by UPLC-MS/MS. Results: Under optimal process conditions, the purity of the polyphenols and the antioxidant activity of the purified product were significantly increased. The purified products contained mainly nine polyphenolic compounds, in order of retention time: p-hydroxybenzoic acid, caffeic acid, vanillin, p-coumaric acid, trans-ferulic acid and salicylic acid. Conclusion: The macroporous resin purification process is effective in enriching bran polyphenols and the resulting purified product has a significantly higher antioxidant capacity, while maintaining the richness of the polyphenolic species.

Keywords

• wheat bran polyphenols
• macroporous resin
• purify
• antioxidant
• hplc-ms/ms
• qualitative analysis