Tea extracts influence on catalytical properties of Fe2plus in lipids
Lipid oxidation process can be catalyzed by the presence of metal ions. The Fe2+ addition to the unsaturated fatty acid leads to creating of active oxygen forms initiating the lipid oxygenation process. It was stated, that the plant extracts addition, possessing metal chelating proprieties, can inhibit these processes. Research investigations were conducted in sunflower oil and lard in Rancimat test conditions. The Yunan tea extracts (Camelia sinensis L.) metal ions chelating and antioxidative activity in presence of Fe2+ was quantified. Strong Fe2+ chelating properties of tea extracts were affirmed, highest for green tea ethanol extract. The oxidative stability analysis of lipids with tea extracts addition showed the tea and solvent as well as extracts concentration dependency, and was higher for green and black tea ethanol extracts. The correlation among Fe2+ chelating ability and tea extracts properties in protection of lipids in Rancimat test was affirmed.