title: Soluble phenolic compounds in fresh and ensiled orchard grass (Dactylis glomerata L.), a common species in permanent pastures with potential as a biomass feedstock.
abstract: High-value coproducts can greatly improve the feasibility of utilizing plant feedstocks for biorefining and biofuel production. Plant polyphenolics have potential application in the pharmaceutical and cosmetic industries. Orchard grass varieties have been noted for accumulation of polyphenolic compounds, and the current study determined the soluble phenol profile and content in the orchard grass variety 'Abertop'. Hydroxycinnamates and flavonoids were monitored during the transition from vegetative to flowering stage at maximum crop yield. Caffeic acid derivatives, related to bioactives in the Asian medicinal herb Salvia miltiorrhiza , and novel hydroxycinnamate-flavone conjugates were also identified in extracts. Harvest yields of hydroxycinnamates and flavonoids ranged from 2.6 to 4.0 kg/ha and from 2.1 to 5.1 kg/ha, respectively. Abundant compounds showed high levels of antioxidant activity comparable with that of trolox. Minimal changes in soluble phenol content and composition were observed after ensiling with the exception of increases in caffeic acid, a caffeic acid derivative, and a caffeic acid breakdown product, dihydroxystyrene.
authors.affiliation: Institute of Biological, Environmental and Rural Sciences, Aberystwyth University , Gogerddan, Aberystwyth, Ceredigion SY23 3EE, United Kingdom.
authors.forename: Barbara
authors.initials: B
authors.lastname: Hauck
authors.forename: Joe A
authors.initials: JA
authors.lastname: Gallagher
authors.forename: S Michael
authors.initials: SM
authors.lastname: Morris
authors.forename: David
authors.initials: D
authors.lastname: Leemans
authors.forename: Ana L
authors.initials: AL
authors.lastname: Winters
mesh_terms: D000821:Animal Feed; D000975:Antioxidants / Q000032:analysis; D056804:Biofuels; D018533:Biomass; D002109:Caffeic Acids / Q000032:analysis; D003373:Coumaric Acids / Q000032:analysis; D031745:Dactylis / Q000737:chemistry*; D005419:Flavonoids / Q000032:analysis; D010636:Phenols / Q000032:analysis*; D059808:Polyphenols / Q000032:analysis; D012820:Silage / Q000032:analysis*; D012995:Solubility
chemical_list: D000975:Antioxidants; D056804:Biofuels; D002109:Caffeic Acids; D003373:Coumaric Acids; D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; C040048:caffeic acid
keywords: Dactylis glomerata; caffeic acid derivatives; flavonoid glycosides; orchard grass; phenolic acid esters