noun, plural: trans fatty acids
A fatty acid in a trans configuration, i.e. two hydrogen atoms adjacent to the double bond are on the opposite side of the chain, thus, resembling the saturated fat in being a straight chain and easily stacked
Unsaturated fatty acids are those containing at least one double bond. This indicates that they can absorb additional hydrogen atoms. One way to classify unsaturated fatty acids is based on their configuration. They may occur in cis or trans configuration. Near the double bond, the two hydrogen atoms stick out either on the same side or on the opposite sides of the chain.
When the two hydrogen atoms stick out on the opposite side of the chain, the fatty acid is said to be in a trans configuration as opposed to the cis configuration wherein the two hydrogen atoms are on the same side. As a result, the trans fatty acid resembles a saturated fatty acid in terms of having a straight chain without bend or kink. The trans fatty acid also tends to be stacked rather easily and therefore turns solid in room temperature.
The cis isomer is the more common than the trans isomer. Only few natural trans fatty acids occur naturally, such as in meat and dairy products. However, the trans isomer can be produced artificially through hydrogenation. Through intense pressure, the hydrogen atoms move to the opposite sides of the chain resulting in trans configuration. Unfortunately, the trans fats are considered harmful to human health. For instance, it lowers high-density lipoprotein (HDL) and increases low-density lipoprotein (LDL).