title: Antioxidant properties of pearled barley fractions.
abstract: Two barley varieties (Falcon and AC Metcalfe) were separated by pearling into seven fractions and subsequently extracted with 80% methanol. The extracts, after solvent removal, were evaluated for their radical scavenging efficacy using Trolox equivalent antioxidant capacity (TEAC). The radical scavenging capacity of the extracts was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, oxygen radical absorbance capacity (ORAC(FL)), and superoxide radical assays and a photoinduced chemiluminescence technique. In both barley varieties the outermost fraction (F1) yielded the highest phenolic content. In general, Falcon had a significantly higher total phenolic content than AC Metcalfe. A similar trend was observed for TEAC, DPPH, and superoxide radical scavenging capacities of the extracts. The contents of water-soluble antioxidants of Falcon and AC Metcalfe were 1.15-12.98 and 2.20-12.25 micromol of Trolox equiv/(g of defatted material), while the corresponding lipid-soluble counterparts varied from 1.44 to 4.70 micromol of alpha-tocopherol equiv/(g of defatted material). Phenolic acids, namely, vanillic, caffeic, p-coumaric, ferulic, and sinapic acids, were identified by HPLC in barley fractions.
authors.affiliation: Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland, A1B3X9, Canada.
authors.forename: Terrence
authors.initials: T
authors.lastname: Madhujith
authors.forename: Marta
authors.initials: M
authors.lastname: Izydorczyk
authors.forename: Fereidoon
authors.initials: F
authors.lastname: Shahidi
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D001713:Biphenyl Compounds; D002839:Chromans; D002851:Chromatography, High Pressure Liquid; D016166:Free Radical Scavengers; D001467:Hordeum / Q000737:chemistry*; D008163:Luminescent Measurements; D010636:Phenols / Q000032:analysis; D010851:Picrates; D017382:Reactive Oxygen Species / Q000737:chemistry; D012639:Seeds / Q000737:chemistry; D013481:Superoxides
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D002839:Chromans; D016166:Free Radical Scavengers; D010636:Phenols; D010851:Picrates; D017382:Reactive Oxygen Species; D013481:Superoxides; C004931:1,1-diphenyl-2-picrylhydrazyl; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid