Journal of the American Oil Chemists' Society

, Volume 80, Issue 9, pp 847–852

Effects of natural antioxidants on iron-catalyzed lipid oxidation of structured lipid-based emulsions


DOI: 10.1007/s11746-003-0784-z

Cite this article as:
Osborn, H.T. & Akoh, C.C. J Amer Oil Chem Soc (2003) 80: 847. doi:10.1007/s11746-003-0784-z


The effects of iron, pH, and natural antioxidants (α-tocopherol, gallic acid, and quercetin) on oxidation of structured lipid-based emulsions were evaluated. Ten percent oil-in-water emulsions were formulated with a canola oil/caprylic acid structured lipid and stabilized with 0.5% whey protein isolate. The PV, anisidine values, and Totox values of emulsions stored at 50°C were measured over a 15-d period. Iron significantly (P<0.05) increased lipid oxidation rates compared to control emulsions. Greater iron-catalyzed lipid oxidation occurred in the pH 3.0 emulsions compared to their pH 7.0 counterparts. Quercetin and gallic acid exhibited significant (P<0.05) prooxidant effects on total oxidation in the pH 3.0 emulsions. Emulsions at pH 7.0 were relatively stable to oxidation throughout the storage period. Because of the ability of some of these natural antioxidants to exhibit prooxidant activity, care should be exercised when adding them to food systems containing transition metals.

Key words

Anisidine valueemulsionsgallic acidiron-catalyzed lipid oxidationperoxide valuequercetinstructured lipidα-tocopherolTotox valuewhey protein isolate

Copyright information

© AOCS Press 2003

Authors and Affiliations

  1. 1.Department of Food Science and TechnologyUniversity of GeorgiaAthens