title: Antioxidant properties of extracts obtained from raw, dry-roasted, and oil-roasted US peanuts of commercial importance.
abstract: Raw, skinless peanut kernels from US commercial production lines were dry- and oil-roasted according to standard industrial practices. Eighty percent (v/v) methanolic extracts from the peanut cultivars were prepared and characterized by RP-HPLC: five predominant compounds were found comprising free p-coumaric acid and potential p-coumaric acid derivatives, as elucidated by DAD-UV spectra with comparisons to those of commercial standards. A Spanish high-oleic peanut possessed the greatest naturally-occurring level of p-coumaric acid and its derivatives, followed by a high-oleic Runner, a normal Runner, and a Virginia peanut. Upon thermal processing, p-coumaric acid was liberated at the expense of its derivatives according to the relationship: oil roasting > dry roasting > raw. A high-oleic Runner exhibited the greatest increase (∼785%) in free p-coumaric acid levels after oil roasting. For many of the samples from the 2007 crop, processing increased the TPC and antioxidant capacities in the order of raw < dry roast < oil roast, but results were cultivar dependent. Oil-roasted peanuts were more effective at scavenging O2(.-) than their dry-roasted counterparts, as determined by a photochemiluminescence assay. Overall findings indicate that although thermal processing altered the composition of peanut kernel antioxidants, TPC values and radical-scavenging activities are preserved. Depending on peanut type, cultivar, and harvest date, enhanced antioxidant capacities can result.
authors.affiliation: Department of Food Science and Technology, The University of Georgia, 100 Cedar Street, Athens, GA 30602-7610, USA.
authors.forename: Brian David
authors.initials: BD
authors.lastname: Craft
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Kosińska
authors.forename: Ryszard
authors.initials: R
authors.lastname: Amarowicz
authors.forename: Ronald Bruce
authors.initials: RB
authors.lastname: Pegg
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000494:pharmacology*; D010367:Arachis / Q000737:chemistry*; D003132:Commerce; D003373:Coumaric Acids / Q000032:analysis / Q000494:pharmacology*; D005511:Food Handling / Q000379:methods; D019301:Oleic Acid / Q000032:analysis / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010938:Plant Oils / Q000032:analysis / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012639:Seeds / Q000737:chemistry*; D014481:United States
chemical_list: D000975:Antioxidants; D003373:Coumaric Acids; D010936:Plant Extracts; D010938:Plant Oils; D017382:Reactive Oxygen Species; D019301:Oleic Acid