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Why do fats and oils contain vitamin E and other minor lipid substances?

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Synthesis of palmitate — Fat Palmitic acid is one of the most prevalent fatty acids occurring in the oils and fats of animals; it also occurs naturally in palm oil. It is generated through the addition of an acetyl group to multiple malonyl groups connected by single bonds between carbons. This structure forms a saturated acid—a major component of solid glycerides.

Natural fats and oils are complex mixtures that consist primarily of triglycerides, which account for 90 to 99 percent of their composition. While these glycerides form the bulk of the substance, natural fats also contain a variety of other minor lipid substances and compounds, including phospholipids, plant steroids (such as sitosterol and stigmasterol), waxes, carotenoids, chlorophyll, and vitamin E.1

The presence of these minor components is a natural characteristic of the biological sources from which fats and oils are derived. Specifically, vitamin E acts as a fat-soluble antioxidant that helps protect the unsaturated fats within the oil from oxidation and rancidity. Because of this protective function, vitamin E is also used commercially as an additive to retard the rancidification of various vegetable oils.23