The use of an enzymatic extraction procedure for the enhancement of highland barley (<i>Hordeum vulgare</i> L.) phenolic and antioxidant compounds

Abstract

Summary A multistep enzymatic extraction method was compared with a conventional chemical extraction process to evaluate the phenolic content and antioxidant activity of highland barley (Z2, Zangqing 25; CHQK , Changheiqingke ). The main phenolic compound extracted was (+)‐catechin, followed by ferulic acid, p ‐coumaric acid, caffeic acid and chlorogenic acid. The multi‐enzymatic digestion yielded a higher retrieval of (+)‐catechin compared to the conventional chemical extraction procedure ( P &lt; 0.05). Compounds obtained from the multi‐enzymatic digestion process exhibited significantly higher ( P &lt; 0.05) antioxidant activities determined by oxygen radical absorbance capacity ( ORAC ) and cellular antioxidant activity ( CAA ) when compared to chemical extracts. These results suggest that highland barley subjected to in vitro multi‐enzymatic digestion exhibits a higher phenolic content and antioxidant activity than the chemical extraction, and this multi‐enzymatic digestion coupled with the CAA assay may be a valuable tool to evaluate the antioxidant potential of wholegrains and fruits, as well as vegetables.