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Why does hydrogenation make fats more resistant to rancidity?

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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.

Hydrogenation makes fats more resistant to rancidity by eliminating the chemical sites most vulnerable to degradation.

Rancidity is primarily caused by the oxidation of unsaturated fatty acids when they are exposed to air. These unsaturated components contain carbon-carbon double bonds, which are highly reactive and susceptible to chemical attack by oxygen. This oxidation process generates volatile compounds, such as aldehydes and ketones, that produce the unpleasant odors and flavors associated with rancid food.12

During the hydrogenation process, hydrogen molecules are added to these double bonds in the presence of a catalyst. By converting these reactive double bonds into saturated bonds, the fatty acid becomes significantly more stable and resistant to oxidation. Consequently, hydrogenated fats are much less likely to become rancid than their unsaturated counterparts.3241