Antioxidant characteristics of phenolipids (quercetin-enriched lecithin) in lipid matrices

A novel phenolipids formulation containing a complex of quercetin and soy lecithin was developed. Antioxidant and antiradical characteristics of native soy lecithin and phenolipids' formulations (complexes of quercetin and lecithin, 1:99 and 3:97, w/w) in the protection of triolein and sunflower oil (SFO) models stored under accelerated oxidative conditions for 15 day at 60 degrees C were studied. Progress of oxidation was monitored by recording the ultraviolet absorptivity and measuring the formation of oxidative products (peroxide value). The antiradical action of different lipid matrices against DPPH. and galvinoxyl radicals was screened during Shaal oven test. The factors influencing the oxidative stability (OS) of different models were also discussed. Inverse relationships were noted between peroxide values and oxidative stabilities at termination of the storage. Absorptivity at 232 nm and 270 nm in models containing lecithin increased gradually with the increase in time, due to the formation of conjugated dienes and polyenes. In general, oxidative stabilities of models enriched with phenolipids' formulations were better than in models containing lecithin or quercetin alone, most likely as a consequence of synergism between polar lipids and quercetin as well as tocopherols. Moreover, increases in concentration of quercetin in pilenolipid formulations resulted in an increase in its antioxidative potential. These results will be useful for improving the antioxidative activity, health impact and functionality of polar lipids and phenolic compounds in different food and pharmaceutical applications. (C) 2011 Elsevier B.V. All rights reserved.