Vegetable oils acids formation during

Release of this alkene from the catalyst surface completes the isomerization. This transformation is exactly what occurs during the partial hydrogenation of vegetable oils, which is the commercial process for the formation of margarine and other partially saturated fats. The trans double bonds in these products— the so-called trans fatly acids— give rise to various adverse health effects that are described in more detail in Real Life 19-3. 

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