Impact of germination pretreatment on the polyphenol profile, antioxidant activities, and physicochemical properties of three color cultivars of highland barley

Abstract

Highland barley (Hordeum vulgare. L) is the staple food resource in the Qinghai–Tibet Plateau of China. The aim of this study was to investigate the effect of germination on the polyphenol profile, antioxidant activities, and physicochemical properties of three color cultivars of highland barley. Ultra-high-performance liquid chromatography coupled to electrospray ionization-time of flight mass spectrometry was applied to separate and characterize 23 polyphenols in barley extract before and after the germination. The heatmap plot revealed that ten polyphenols were up-regulated, and seven were down-regulated. In the physicochemical characterization studies, the water-holding capacity, water-solubility index, fat-absorption capacity, and foaming capacity of germinated barley flours were increased significantly. Moreover, germination also resulted in a significant increase in higher transition temperatures values and lower enthalpy values in these barley flour. Our results may help in understanding the influence of germination on the functional properties of highland barley and choosing appropriate applications to promote the utilization of germinated highland barley in the food industry.