Method development for monitoring seal blubber oil oxidation based on propanal and malondialdehyde formation

Abstract

Omega-3 polyunsaturated fatty acids (PUFA) in fish oils are extremely susceptible to oxidation and rapid degradation. Many studies have shown the health benefits of omega-3 fatty acids for human beings thus lead to the effort in improving the stability of these oils. Propanal, which is specific formed from the oxidation of omega-3 PUFA, could be used as an indicator of the extent of seal blubber oxidation. Solid-phase microextraction (SPME) is a solvent-free volatile extraction method and has been widely used in volatile analysis. However, short-chain aldehydes like propanal do not bind to the fiber. We have developed a rapid method to determine the extent of lipid oxidation of seal blubber oil based on propanal and malondialdehyde formation. O-(2,3,4,5,6-Pentafluorobenzyl) hydroxylamine hydrochloride (PFBHA) was used as derivatization agent to ensure the binding of short chain aldehydes to SPME fiber. Comparing with other traditional methods for measuring lipid oxidation, our method is convenient and reduces the amount of toxic solvent used. It targets the major end products produced by polyunsaturated omega-3 fatty acids oxidation, propanal and malondialdehyde. © 2007 American Chemical Society.