What effect does partial hydrogenation have on fats?

Partial hydrogenation of fats refers to the process where hydrogen is added to unsaturated fatty acids, which can convert some of the cis double bonds present in these fatty acids to trans double bonds. This transformation occurs because during partial hydrogenation, not all of the double bonds are saturated, but those that are converted can take on a trans configuration, which is characteristic of trans fats. Trans fats have unique properties, such as a higher melting point compared to their cis counterparts, which can affect their behavior in foods.

In contrast, the effects of partial hydrogenation on fats would not include increasing the total double bond count, as it primarily modifies existing double bonds. The melting temperature usually tends to increase with the formation of trans fats due to their straighter molecular structure, unlike the kinked structure of cis fats. Additionally, partial hydrogenation does not eliminate all unsaturations—some double bonds remain—instead, it selectively alters certain bonds while leaving others intact. Therefore, the correct understanding of the process highlights the creation of fats with trans double bonds as a significant outcome of partial hydrogenation.