Effect of α- And δ-tocopherol on the oxidative stability of a mixed hydrogenated fat under frying conditions

Malgorzata Nogala-Kalucka, Jozef Korczak, Ibrahim Elmadfa, Karl Heinz Wagner

Veröffentlichungen: Beitrag in FachzeitschriftArtikelPeer Reviewed

Abstract

Information on the antioxidative potential of δ-tocopherol is scanty, in particular for frying conditions. This study was aimed at assessing the antioxidative effects and degradation of α- and δ-tocopherol between 0.01 and 0.1% on the oxidation of a commercial frying fat at 160 °C. Oxidation experiments were performed by assessing every 15 or 30 min the peroxide value and conjugated dienes as primary oxidation products, p-anisidine reactive products and hexanal as secondary oxidation products, as well as the stability of tocopherols. The fatty acid composition was determined after 6 h. The fat samples enriched with α-tocopherol were considerably less resistant to oxidation compared to those with δ-tocopherol. Both primary and secondary oxidation parameters increased their speed of formation with α-tocopherol but not with δ-tocopherol. The latter observation is confirmed for the total amount of oxidation and also for the first stage, showing a "lag phase" only for δ-tocopherol. These antioxidative effects can be due to the higher stability of δ-tocopherol compared to α-tocopherol, which is oxidized faster into tocopheryl radicals, which can participate in side reactions that result in an acceleration of the oxidation speed. Neither α-tocopherol nor δ-tocopherol influenced the fatty acid pattern. The investigation showed that during mild frying conditions the tocopherol homologues displayed various antioxidant activities. The less effective homologue, α-tocopherol, underwent disintegration more quickly than δ-tocopherol.

OriginalspracheEnglisch
Seiten (von - bis)291-297
Seitenumfang7
FachzeitschriftEuropean Food Research and Technology
Jahrgang221
Ausgabenummer3-4
DOIs
PublikationsstatusVeröffentlicht - Aug. 2005

ÖFOS 2012

  • 303009 Ernährungswissenschaften

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