Fluorescence study of the pro-oxidant effect of free fatty acids on marinelipids

The free fatty acid (FFA) effect on the oxidative stability of marine lipid s was studied by fluorescence assessment. Under different reaction conditio ns, including time, temperature and FFA content and type (different chain l engths and unsaturation degrees), FFAs were made to interact in model syste ms with a commercial marine oil (cod liver oil) and two different fish (hak e and pout) white muscles. Fluorescence assessment showed a pro-oxidant eff ect of all types of FFA, which increased with time, temperature and FFA con tent in the reaction mixtures. At 30 degreesC a higher degree of oxidation was obtained in systems including the shorter-chain-length fatty acids (lau ric and myristic) compared to systems including the longest ones (arachidic and stearic). At the same temperature an increasing pro-oxidant effect was also observed with increasing degree of fatty acid unsaturation (stearic < oleic < linoleic < linolenic). When a lower temperature (-10 <degrees>C) w as tested, a differential pro-oxidant effect among fatty acids (chain lengt h and unsaturation degree) was not observed. (C) 2001 Society of Chemical I ndustry.