Effect of partially hydrolysed lipids on inhibition of oxidation of marine lipids

The role of partially hydrolysed glyceride compounds (monoglycerides, MG; diglycerides, DG) on the protective effect of a natural antioxidant (citric acid) in a commercial marine oil (cod liver oil) was investigated during heat treatment. The development of lipid oxidation was analysed by fluorescence and browning detections. An inhibitory effect of the antioxidant action was observed at 50 degreesC for all the concentrations tested (MG: 0.1-5.0%; DG: 0.1-2.0%), which became faster as the hydrolysed lipid was employed in a higher proportion; no inhibitory action of MG and DG was observed at the same concentrations when lower temperatures (15 and 30 degreesC) were tested. MG including four different branched fatty acids (lauric, myristic, palmitic and stearic) were compared; the inhibitory effect on the citric acid action was found to be faster and higher when the fatty acid chain was longer.