The content of primary (PO) and secondary (SO) oxidation products of canola oil was measured, and a good correlation obtained between them (R2 = 0.991). Peroxide value showed the highest contribution (53.69%) to the PO, whereas its contribution to the SO was much less significant (0.36%). Acid value contribution to the production of hydroperoxides and carbonyls was 12.75% and 29.82%, respectively. Polyene index showed a relatively low contribution to the PO (6.71%) but contributed highly to the SO (21.82%). Tocopherols were more effective to prevent the production of hydroperoxides (14.77%) than of carbonyls (4.36%). In contrast, phenolics were found to be better than tocopherols to resist off-flavours production (11.64% vs. 3.36%). Total polar compounds had a pronounced contribution to creation of offflavours (32.00%) as well as a marked effect on the PO (8.72%).

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