Antioxidant activity of Qingke (highland hull‐less barley) after extraction/hydrolysis and in vitro simulated digestion

This study investigated the antioxidant activity of Qingke by three spectrophotometric assays, namely, 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2′-diphenyl-1-picrylhydrazyl (DPPH), and oxygen radical absorbance capacity (ORAC) assays, after two pretreatments (extraction/hydrolysis and in vitro simulated digestion). Results showed that the three assays and the two pretreatments obtained different values and orders of the antioxidant capacities of the Qingke varieties. Correlation analysis revealed that the correlations between total antioxidant capacities detected by ABTS and ORAC assays (R2 = 0.726, p < .01) were stronger than those between DPPH and ORAC assays (R2 = 0.488, p < .05). The ABTS scavenging activities and ORAC values of the tested Qingke varieties after the in vitro simulated digestion were significantly higher (p < .05) than those after the extraction/hydrolysis. Practical applications Qingke is an ancient hull-less barley cultivar that grows in highlands. It exhibits a unique antioxidant compound profile and shows potential in oxidative stress mitigation. Systematically investigating the antioxidant activity of Qingke provides insights into its real antioxidant potential and presents scientific evidence for its future economic consumption.