Ai. Hopia et al., APPLICATION OF HIGH-PERFORMANCE SIZE-EXCLUSION CHROMATOGRAPHY TO STUDY THE AUTOXIDATION OF UNSATURATED TRIACYLGLYCEROLS, Journal of the American Oil Chemists' Society, 70(8), 1993, pp. 779-784
A combination of solid-phase extraction (SPE) and high-performance siz
e-exclusion chromatography (HPSEC) was used to study the autoxidation
of triacylglycerol (TAG) mixtures separated from low-erucic acid rapes
eed oil and butter oil. The samples were autoxidized in the dark at 40
-degrees-C for four weeks. The polar compounds of the autoxidated samp
les were separated by SPE (NH2 stationary phase), and the polar fracti
on was further characterized by HPSEC with a series of three size-excl
usion columns and an evaporative light-scattering detector. The polar
fraction contained TAG polymers, polar TAG monomers (PTAG) and diacylg
lycerols. Peroxide values and anisidine values of the samples were als
o measured. By using three different types of TAG mixtures, it could b
e demonstrated that the PTAG content of the TAGs increases during auto
xidation. A slight increase was also detected in polymer content. The
correlation between PTAG content and the comparative measurements was
considered significant. The results indicate that the measurement of P
TAG and polymeric material content by HPSEC analysis can be used when
studying the autoxidation level of edible oils and in characterizing t
he autoxidation products of different molecular sizes.