Inhibition by polyphenols containing OH groups at different positions in the presence of lecithin

Resumo

An inhibition by the semisynthetic polyphenols bearing bicyclic isobornyl substituents and OH groups arranged variously relative to each other was investigated in the presence of lecithin. A decreased efficiency of the inhibition by the phenolic antioxidants in the presence of soy bean lecithin, which manifests itself as the increased initial oxidation rate, has been revealed. The most significant changes in the inhibitory effect were found for a polyphenol containing the OH groups at the meta position, while those the smallest ones were observed for the para position relative to each other. In the case of meta-substituted polyphenol, the decreased stoichiometric inhibition coefficient was observed along with the increased initial oxidation rate. The formation of lecithin complexes with polyphenols was detected by UV-Vis and IR spectroscopy, which leads to a decrease in their inhibitory effect.