title: LC-MS analysis of phenolic compounds and antioxidant activity of buckwheat at different stages of malting.
abstract: The impact of malting on the profile of the phenolic compounds and the antioxidant properties of two buckwheat varieties was investigated. The highest relative increases in phenolic compounds were observed for isoorientin, orientin, and isovitexin, which are consequently major inducible phenolic compounds during malting. Only a minor relative increase was observed for the most abundant phenolic compound, rutin. The radical-scavenging activity of buckwheat seeds was evaluated using ABTS and DPPH assays. A considerable increase in total phenolic compounds and higher antioxidant activity were observed after 64h of germination, whereas kilning resulted in decreased total phenolic compounds and antioxidant activity. Higher antioxidant activities for extracts were found for buffered solvents than for pure methanol and water. Changes in the composition of the phenolic compounds and increased antioxidant content were confirmed by several methods, indicating that buckwheat malt can be used as a food rich in antioxidants.
authors.affiliation: Biotechnical Faculty, University of Ljubljana, SI-1111 Ljubljana, Slovenia.
authors.forename: Petra
authors.initials: P
authors.lastname: Terpinc
authors.affiliation: Biotechnical Faculty, University of Ljubljana, SI-1111 Ljubljana, Slovenia.
authors.forename: Blaž
authors.initials: B
authors.lastname: Cigić
authors.affiliation: Biotechnical Faculty, University of Ljubljana, SI-1111 Ljubljana, Slovenia.
authors.forename: Tomaž
authors.initials: T
authors.lastname: Polak
authors.affiliation: Biotechnical Faculty, University of Ljubljana, SI-1111 Ljubljana, Slovenia.
authors.forename: Janez
authors.initials: J
authors.lastname: Hribar
authors.affiliation: Biotechnical Faculty, University of Ljubljana, SI-1111 Ljubljana, Slovenia. Electronic address: tomaz.pozrl@bf.uni-lj.si.
authors.forename: Tomaž
authors.initials: T
authors.lastname: Požrl
mesh_terms: D047310:Apigenin / Q000032:analysis; D002853:Chromatography, Liquid; D019612:Fagopyrum / Q000737:chemistry*; D005419:Flavonoids / Q000032:analysis; D018525:Germination; D005960:Glucosides / Q000032:analysis; D013058:Mass Spectrometry; D000432:Methanol; D010084:Oxidation-Reduction; D010636:Phenols / Q000032:analysis*; D010936:Plant Extracts / Q000737:chemistry*; D012431:Rutin / Q000032:analysis; D012639:Seeds / Q000737:chemistry*
chemical_list: D005419:Flavonoids; D005960:Glucosides; D010636:Phenols; D010936:Plant Extracts; D012431:Rutin; D047310:Apigenin; C065886:orientin; C049772:isovitexin; D000432:Methanol
keywords: Antioxidant activity; Buckwheat; LC–MS; Malting; Phenolic compound profile; Solvent composition