1, hydrogenated vegetable oil
Hydrogenated vegetable oil is the main food source of trans fatty acids. Vegetable oil, mainly unsaturated fatty acids, is hydrogenated and hardened under pressure and the action of catalysts such as nickel, and changes from liquid unsaturated fatty acids to solid or semi-solid saturated fatty acids. However, during the treatment, a part of unsaturated fatty acids in vegetable oil changed from cis-unsaturated fatty acids with natural framework to trans-unsaturated fatty acids.
2. Refined vegetable oil
When natural vegetable oil is refined and deodorized, dienoic acid esters and trienoic acid esters in polyunsaturated fatty acids will undergo thermal polymerization and trans isomerization to produce trans fatty acids. Trans fatty acids produced in hydrogenated oils and refined vegetable oils are collectively referred to as IP- trans fatty acids.
3. Fat tissue and milk of ruminants
In the rumen of ruminants, polyunsaturated fatty acids (PUFA) in feed will produce a large number of trans fatty acid isomers under the enzymatic biohydrogenation of rumen microorganism Vibrio butyricum, mainly T118:1(vacuum), and also contain a large amount of * *.
Method for controlling trans fatty acids
1, control the intake of edible oil. Refined vegetable oil also contains a small amount of trans fatty acids, and most of the edible oil purchased by daily residents is refined vegetable oil. Dietary Guidelines for China Residents recommended that the daily intake of vegetable oil should be controlled at 25-30g.
2. Carefully eat processed foods containing hydrogenated vegetable oil. Foods such as hydrogenated vegetable oil, cocoa butter substitute, margarine, shortening, vegetable butter and artificial shortening in the ingredients list should not be eaten too much.