We. Neff et M. Elagaimy, EFFECT OF LINOLEIC-ACID POSITION IN TRIACYLGLYCEROLS ON THEIR OXIDATIVE STABILITY, Lebensmittel-Wissenschaft + Technologie, 29(8), 1996, pp. 772-775
Four synthetically produced triacylglycerols containing linoleic and p
almitic acid in different known positions were used to determine the e
ffect of fatty acid position on their relative rates of autoxidation.
The triacylglycerols were sn-1,3-dipalmitoyl-sn-2-linoleoyl (PLP); sn-
1,2(2,3)-dipalmitoyl-sn-1(3)-monolinoleoyl (PPL); sn 2-palmitoyl-sn-1,
3-dilinoleoyl (LPL); and sn 1 (3)-palmitoyl-sn-1,2(2,3)-dilinoleoyl (P
LL) glycerols. Oxidation was evaluated both by peroxide value, and rev
ersed phase HPLC with ultraviolet absorbance detection at 235 nm for c
onjugated diene of triacylglycerol's oxidized linoleic acid. Triacylgl
ycerols were oxidized at 60 degrees C in the dark. PLL had lower oxida
tive stability than LPL. This effect may be due to easier interactions
between adjacent linoleic acid of PLL compared to nonadjacent linolei
c acid of LPL during autoxidation. PLP had lower oxidative stability t
han PPL. Reversed phase HPLC analysis showed that at a low oxidation l
evel, PLP and PPL produced monohydroperoxide and LPL and PLL produced
both mono- and bishydroperoxides. These results are further evidence t
hat fatty acid position on triacylglycerols plays a role in lipid oxid
ation.