Studies of differently-induced peroxidation phenomena in lecithins

Egg and soya phospholipids, in the form of liposomes, were analyzed to evaluate lipid peroxidation by means of UV and fluorescence measurements. Oxidation processes were induced by different methods: sonication, UV radiation, and incubation with ferrous ions/ascorbic acid. Aging effect and pH influence were also investigated. The obtained results showed that tested vegetable phospholipids, because of their higher content in polyunsaturated fatty acids, were in all cases much more rapidly oxidized with respect to the animal ones; furthermore, an inverse relationship between the starting hydroperoxide level and the oxidation rate of phospholipids was observed. In the case of soya lecithin a sharp increase in the peroxidation rate was appreciated in slightly alkaline environmental conditions. No effects on peroxidation were ever observed when UV radiations with λ = 254 nm were used.