title: Gamma radiation effects on peanut skin antioxidants.
abstract: Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to refined-bleached-deodorized (RBD) soybean oil. The oxidative stability of the oil samples was determined using the Oil Stability Index method and compared to a control and synthetic antioxidants (100 mg/kg BHT and 200 mg/kg TBHQ). Gamma radiation changed total phenolic content, total condensed tannins, total flavonoid content, and the antioxidant activity. All extracts, gamma irradiated or not, presented increasing induction period (h), measured by the Oil Stability Index method, when compared with the control. Antioxidant activity of the peanut skins was higher than BHT. The present study confirmed that gamma radiation did not affect the peanut skin extracts' antioxidative properties when added to soybean oil.
authors.affiliation: Center for Nuclear Energy in Agriculture, University of São Paulo (CENA/USP), Av. Centenário 303, P.O. Box 96, 13400-970, Piracicaba, SP, Brazil.
authors.forename: Adriano Costa
authors.identifier: 0000-0001-9404-1193
authors.initials: AC
authors.lastname: De Camargo
authors.affiliation: Department of Agri-Food Industry, Food & Nutrition, "Luiz de Queiroz" College of Agriculture (ESALQ/USP), University of São Paulo, Av. Pádua Dias 11, P.O. Box 9, CEP 13418-900, Piracicaba, SP, Brazil.
authors.forename: Thais Maria Ferreira de Souza
authors.initials: TMFS
authors.lastname: Vieira
authors.affiliation: Department of Agri-Food Industry, Food & Nutrition, "Luiz de Queiroz" College of Agriculture (ESALQ/USP), University of São Paulo, Av. Pádua Dias 11, P.O. Box 9, CEP 13418-900, Piracicaba, SP, Brazil.
authors.forename: Marisa Aparecida Bismara
authors.initials: MAB
authors.lastname: Regitano-D'Arce
authors.affiliation: Department of Agri-Food Industry, Food & Nutrition, "Luiz de Queiroz" College of Agriculture (ESALQ/USP), University of São Paulo, Av. Pádua Dias 11, P.O. Box 9, CEP 13418-900, Piracicaba, SP, Brazil.
authors.forename: Maria Antonia
authors.initials: MA
authors.lastname: Calori-Domingues
authors.affiliation: Department of Agri-Food Industry, Food & Nutrition, "Luiz de Queiroz" College of Agriculture (ESALQ/USP), University of São Paulo, Av. Pádua Dias 11, P.O. Box 9, CEP 13418-900, Piracicaba, SP, Brazil.
authors.forename: Solange Guidolin
authors.initials: SG
authors.lastname: Canniatti-Brazaca
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000528:radiation effects*; D010367:Arachis / Q000737:chemistry* / Q000528:radiation effects*; D005419:Flavonoids / Q000032:analysis / Q000528:radiation effects; D005514:Food Irradiation; D005720:Gamma Rays; D010936:Plant Extracts / Q000737:chemistry / Q000528:radiation effects; D059808:Polyphenols / Q000032:analysis / Q000528:radiation effects; D044945:Proanthocyanidins / Q000032:analysis / Q000528:radiation effects; D012639:Seeds / Q000737:chemistry / Q000528:radiation effects; D013024:Soybean Oil / Q000737:chemistry
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010936:Plant Extracts; D059808:Polyphenols; D044945:Proanthocyanidins; D013024:Soybean Oil