1 Lipid Technology 2007 Vol: 19(1):9-11. DOI: 10.1002/lite.200600003

Degradation products formed from long‐chain PUFA during deodorization of fish oil

Omega-3 long-chain polyunsaturated fatty acids (LC-PUFA) are sensitive to heat and may be destroyed by thermal processes such as deodorization. For example, deodorization of fish oil may induce polymerization, geometrical isomerization and cyclization of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. In this paper, we review our main findings on the effects of deodorization at three different temperatures on semi-refined fish oil LC-PUFA. Cyclic structures have been elucidated and mechanisms responsible for ring formation have been discussed. Polymers were found to be the most abundant degradation products formed during fish oil deodorization. A method for quantitative measurement of geometrical isomers of EPA and DHA by gas-liquid chromatography (GLC) has been developed and validated. Overall assessment of the results obtained with this method suggests that deodorization at temperatures above 180°C affects the quality and the content of LC-PUFA in fish oil.