Antioxidant activity of minor amounts of γ-tocopherol in natural triacylglycerols

  • Anna-Maija Lampi
  • Anu Hopia
  • Vieno Piironen
Article

Abstract

The effects of minor amounts of γ-tocopherol on the oxidation of natural triacylglycerols (TAG) of rapeseed (RO) and butter oils (BO) were studied. Four different TAG materials were blended from chromatographically purified TAG that contained 100–25% of RO TAG. The RO TAG contained from <1 to 43 µg γ-tocopherol per gram of TAG, which corresponded to ≤6% of the total tocopherols in the original RO. The TAG were held at 40°C in the dark for 4 wk and followed at regular intervals by measurements of hydroperoxide formation by peroxide values and of secondary product formation by p-anisidine values at regular intervals. In all TAG, minor amounts of γ-tocopherol retarded oxidation. In RO TAG, concentrations as low as 11 µg/g of γ-tocopherol (1.5% of the total tocopherols in the original RO) were enough to decrease hydroperoxide and secondary product formation to 46 and 39%, respectively. The effect was even more important in TAG mixtures that contained BO TAG. There were no significant differences between oxidation of the RO TAG at 24 µg/g, the 75% RO TAG mixture at 11 µg/g, and the 50% RO TAG mixture at 3 µg/g of γ-tocopherol. Even at these minor levels, γ-tocopherol was a significant antioxidant, which is important in oxidation studies of purified model systems.

Key Words

Antioxidant natural triacylglycerols γ-tocopherol 

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Copyright information

© AOCS Press 1997

Authors and Affiliations

  • Anna-Maija Lampi
    • 1
  • Anu Hopia
    • 1
  • Vieno Piironen
    • 1
  1. 1.Department of Applied Chemistry and Microbiology, Viikki-DUniversity of HelsinkiHelsinkiFinland

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