Czech J. Food Sci., 2012, 30(4):351-357 | DOI: 10.17221/174/2011-CJFS

Ability of phenolic acids to protect naturally present alfa-tocopherol during the heating of plant oils

Zuzana RÉBLOVÁ, Jakub FIŠNAR, Dana TICHOVSKÁ, Marek DOLEŽAL, Kristýna JOUDALOVÁ

Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology Prague, Prague, Czech Republic

The ability of phenolic acids (ferulic, gallic, protocatechuic, and sinapic; 600 mg/kg) to protect naturally present a-tocopherol was tested during the heating of sunflower oil on a hot plate set at 120, 150, 180, 210, or 240°C, and during the heating of rapeseed, olive and soybean oils on a hot plate set at 180°C. In all the studied conditions, a-tocopherol was significantly protected only by gallic acid. This phenolic acid prolonged the half-life of a-tocopherol (calculated as the time needed for the a-tocopherol content to decrease to 50% of the original value) typically two- to four-fold. Hence the ability of phenolic acids to protect a-tocopherol in bulk oils does not markedly depend on the experimental conditions as is seen in antioxidant activity, i.e. in the ability of antioxidants to protect fatty acids.

Keywords: vitamin E; lipid oxidantion; antioxidants; frying

Published: August 31, 2012  Show citation