Effect of season, feeding, and anatomical region on the triacylglycerol profile of Iberian pig fat

The work studies the effects of season, feeding type, and anatomical region on the Iberian pig fat triacylglycerol (TAG) profiles, considered as compositional data (CoDa). The analysis consisted of applying exploratory tools in the simplex and standard multivariate techniques to data transformed into the Euclidean space (ilr coordinates). Compositional biplot showed differences in TAG containing palmitic (P) and oleic (O) acids between the 2005 and 2003/2004 seasons but not within these. PPP (clr variance, 0.139), OLL (0.095), PPS (0.075), POPo + PLP (0.074), and PSS (0.629) showed high CoDa variability among treatments. The ANOVA analysis found significant (p ≤ 0.05) effects of season, feeding type, and anatomical region on pig fat TAG profile, but only that for 2005 season was well predicted (97.5%) by discriminant analysis (DA). Overall, season was more influential on the Iberian pig fat TAG profile than montanera length and sampling region, which effects were not significant for some statistical techniques.