The Antioxidant Properties of Four Korean Barley Cultivars at Different Harvest Times and Profiling of Major Metabolites

Abstract

Young barley leaves (YLB) have been no studies comparing the antioxidant activities of various cultivars, or differences the antioxidant activity at different harvest times. The objective of this study was to evaluate the differences in the antioxidant activities of YLB by different cultivars and growth stages. The 4 Korean YLB, Nakyoung, Dahyang, Saegang, and Boanchal, were sprouted, and their total polyphenols, total flavonoids, and ABTS radical cation (ABTS•+) scavenging activity were measured. The 4 cultivars exhibited high total polyphenol contents (TPC) and total flavonoid contents (TFC), with a range of 1047.8–1263.2 GAE mg·100 g-1 and 443.7–550.7 CE mg·100 g-1, DW, respectively. In addition, they exhibited high levels of ABTS•+ (RC50 value range of 41.8–80.8 μg·mL-1) scavenging activity. After sprouting, the antioxidant activity of the 4 cultivars increased. That is, in these YLB, the TPC, TFC and radical scavenging ability were enhanced by sprouting. Lutonarin (LN) and saponarin (SN) are the major compounds of YLB. LN exhibited stronger radical scavenging activity than SN. Over time, LN contents increased and SN contents decreased. As a result, the antioxidant ability of YLB was improved with increased growing time.