title: Physicochemical properties of natural phenolics from grapes and olive oil byproducts and their antioxidant activity in frozen horse mackerel fillets.
abstract: The reducing and chelating capacities and the affinity for the incorporation into the fish muscle of grape procyanidins, hydroxytyrosol, and propyl gallate were studied together with their antioxidant activity in frozen horse mackerel (Trauchurus trauchurus) fillets. Fillets were supplemented with phenolic antioxidants by (a) spraying an aqueous phenolic solution, (b) glazing with an aqueous phenolic solution, and (c) a previous washing of fillets with water plus spraying an aqueous phenolic solution. The effect of washing on the endogenous pro-oxidant/antioxidant balance of the fillets was also determined. All phenolic compounds were effective delaying lipid oxidation in the fish fillets. The order of antioxidant efficiency in spraying and glazing was propyl gallate > hydroxytyrosol > procyanidins, which was similar to the reducing power of these phenolics, but did not show any correlation with their chelating capacity and their affinity to the fish muscle. Washing the fillets with water prior to spraying phenols increased synergistically the antioxidant activity of grape procyanidins and changed the relative antioxidant efficiency to propyl gallate approximately procyanidins > hydroxytyrosol. This synergism may be a result of a better distribution of the procyanidins onto the fillet surface because of the residual water that remained on the fillets surface after washing.
authors.affiliation: Instituto de Investigaciones Marinas (CSIC), Eduardo Cabello 6, 36208 Vigo, Spain. mpazos@iim.csic.es
authors.forename: Manuel
authors.initials: M
authors.lastname: Pazos
authors.forename: Ana
authors.initials: A
authors.lastname: Alonso
authors.forename: Juan
authors.initials: J
authors.lastname: Fernández-Bolaños
authors.forename: Josep L
authors.initials: JL
authors.lastname: Torres
authors.forename: Isabel
authors.initials: I
authors.lastname: Medina
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005519:Food Preservation; D005615:Freezing; D005638:Fruit / Q000737:chemistry*; D000069463:Olive Oil; D010473:Perciformes; D010636:Phenols / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives / Q000494:pharmacology; D010938:Plant Oils / Q000737:chemistry*; D044945:Proanthocyanidins / Q000494:pharmacology; D011435:Propyl Gallate / Q000494:pharmacology; D027843:Vitis / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; D044945:Proanthocyanidins; C005975:3,4-dihydroxyphenylethanol; D011435:Propyl Gallate; D010626:Phenylethyl Alcohol