How is the molecular structure changed in the hydrogenation process? Let’s look at our 18-carbon fatty acids again. Stearic acid is fully saturated, with 2 hydrogen atoms attached to every carbon atom. Each pair of hydrogen atoms forms an electron cloud. Oleic acid has two hydrogen atoms on the same side at the bend of the double bond. This is called the cis configuration; the two hydrogen atoms are next to each other and form an electron cloud. During the hydrogenation process, one of the hydrogen atoms is moved to the other side so that the hydrogen atoms are now across from each other—this is called the trans configuration ( trans means across) and this is what is meant by a trans fatty acid. With the 2 hydrogen atoms on opposite sides, the molecule straightens out and now has many of the same qualities as a saturate. It will be solid at room temperature and can be used as a shortening in baked goods. However, in our cell membranes, the trans fat has very different characteristics from a saturated fat or monounsaturated fat. Your body makes chemical reactions where there are electron clouds, but it cannot do this when the cell membrane contains lots of trans fatty acids. With a trans fatty acid, instead of an electron cloud, there is a dead spot. The more partially hydrogenated oils containing trans fatty acids that you eat, the more trans fats you will have in your cell membranes and the more chaos you will have at the cellular level.
The problem with damaged polyunsaturated fatty acids is that they are very reactive, and start to cause undesirable changes in the tissues, including the arteries. Saturated fats do not cause these changes. Make no mistake: it is not saturated fats that contribute to heart disease, and not monounsaturated fatty acids, but the rancid and processed polyunsaturated vegetable oils.
Trans fatty acids
TRANS FATTY ACIDS
Pradeep Chaminda Weerathunga
Seminar in Food Science & Technology
Major Food Sources of Artificial Trans Fat for
Major Food Sources of Artificial Trans
Long shelf life
Stability during deep-frying
Ability to enhance the palatability of food
Contain double bonds
Rise LDL level less
than SFs do
Reduce HDL level
consumption- 2.6% of
total calorie intake
No double bonds
Rise LDL level more
than TFAs do
Rise HDL level
of total calorie intake
Look the ingredients list
“partially hydrogenated,” “shortening,” “margarine”?
Check the Nutrition Facts panel
TFAs 0.5g per serving
Ask from manufacturer
Mainly due to the trend of McDonald’s and
KFC restaurant chains.
Especially focuses on middle and upper
classes of people.
Use of vegetable oils in cooking.
Consumption of fried food such as