Determination of positional distribution of polyunsaturated fatty acids in natural and processed fish oil by 13 C-NMR
Fish oil is a rich source of n-3 polyunsaturated fatty acids(PUFA).In order to clarify the positional distribution of PUFA in fish oil,gas chromatography(GC)was used to determine the total fatty acid composition of 4 kinds of natural fish oil and 3 kinds of processed fish oil,and 13 C-nuclear magnetic resonance(13C-NMR)was used to analyze the positional distribution of PUFA.At the same time,the positional distribution of saturated fatty acids(SFA)and monounsaturated fatty acids(MUFA)on triacylglycerol(TAG)in 4 natural fish oils were analyzed using the alcoholysis of Novozym 435 combined with GC.The results showed that the contents of docosahexaenoic acid(DHA)and eicosapentaenoic acid(EPA)in processed fish oil generally higher than that in natural fish oil,with DHA content of 28.43％-76.63％and EPA content of 12.72％-56.37％.DHA in natural fish oils was mainly esterified at the sn-2 position(relative content of sn-2 DHA 50.39％-63.71％),while that in processed fish oils was in a random distribution state(relative content of sn-2 DHA 28.78％-36.76％).There was no clear distribution pattern of SFA and MUFA in different natural fish oils.In conclusion,the processing technology of fish oil can increase the content of total DHA,but change the positional distribution of DHA on the TAG glycerol backbone.
fish oilprocessing technologysn-2 fatty acid13C-NMRDHA
NETL
NSTL
万方数据
维普
