.
Finally the WEWO (Without Oil) and WEPO (Palm Oil) formulas
which were designed to be poor in fatty matter and not prone to oxidation
did not correlate positively with any of these LO aldehydes.
Fig. 4 shows FDA made exclusively on the ten LO saturated aldehydes
found in all formulas. The first axis (81.68% information) discriminates
formulas into two groups: that containing egg yolk
(FEPO) and the four remaining ones made by egg white (WEWO,
WESO, WESsO, WEPO). The second axis (15.75% information)
shows sample separation following the absence of endogenous
antioxidants. As a result, formulas are gathered into three groups:
FEPO alone, WEsSO alone and (WESO, WEPO and WEWO).
The WEsSO recipe is mainly characterised by short chain aldehydes
(C6–C9). These compounds could be formed by auto-oxidation
of unsaturated fatty acids, mainly hexanal from C18:2 and the
others from C18:1 (Whitfield, 1992).