Hardening Vegetable Oils Through Hydrogenation | Organic Chemistry | Chemistry | FuseSchool

Hardening Vegetable Oils Through Hydrogenation | Organic Chemistry | Chemistry | FuseSchool


We have previously learned that an emulsion
is a mixture of two immiscible liquids stabilized by an emulsifier. Margarine is a very good example of an emulsion. In this lesson, we will learn about margarine
– what it is, how it is made, and a few key properties. Vegetable oils are polyunsaturated fats. You may be familiar with the term unsaturated
to describe the presence of C=C double bonds within a hydrocarbon structure. So a polyunsaturated fat will have many double
bonds within its structure. These fats are normally liquids at room temperature. We can hydrogenate, or “add hydrogens”
to C=C double bonds by passing hydrogen gas over these molecules in the presence of a Pt catalyst
at 60⁰C. This is, and you got it, called a hydrogenation
reaction. When these fats are hydrogenated, they are
“hardened”. Hydrogenated fats have a higher melting point,
and as a result, are usually solids at room temperature. Let’s think about margarine and what it
is used for – it is usually spread on bread, or used in baking. We can use a spoon and scoop spoonfuls out. It is usually stored in a plastic container,
and it takes the shape of the container. Keeping in mind the properties and consistency
of margarine, do you think ALL the double bonds are hydrogenated, or only SOME of the
double bonds? Please pause the lesson to think about this,
and resume when you are done. In the production of margarine, only some
of the double bonds of the polyunsaturated vegetable oils are hydrogenated. This is called partial hydrogenation. So, the vegetable oil used is not fully solidified. “Softer” and “easier to spread” margarine
is less hydrogenated, whereas “harder” margarine is more hydrogenated. Are you thinking about the taste of margarine
now? Is your mouth watering? Do you feel like toasting a slice of bread
and spreading margarine over it? Here is a bigger question: Can you taste the
saltiness of margarine? As mentioned in the introduction, margarine
is an emulsion of water droplets in oil. These water droplets are in fact salty water
– this is why margarine usually has a salty taste. The salt content of margarine can be modified
– we have low sodium margarine, “regular” margarine, and even salt-free margarine! The emulsifier that is commonly added is lecithin,
the same emulsifier used to stabilize ice cream! In conclusion, margarine is an emulsion of
partially hydrogenated vegetable oils and salty water. When vegetable oils are hydrogenated, a molecule
of hydrogen is added across a C=C double bond. This “hardens” the oil, and the degree
of hydrogenation can be varied to give softer or harder oils.

17 thoughts on “Hardening Vegetable Oils Through Hydrogenation | Organic Chemistry | Chemistry | FuseSchool”

  1. 1:59 – carbon atoms must have four bonds. In this video they have two bonds with oxigen, one with hydrogene and one with oxigen also. Total – five bonds. Correct the video, take off an extra hydrogene atom.

  2. Man..! You´re awesome, you saved me, it´s so damn simple..! Thank you thank you thank you, like and a New Subscriber Added to you man..!

  3. To any English people watching this video please DON'T put a platinum catalyst it is a NICKEL catalyst. If you put platinum in your science test YOU WILL NOT get the mark!

Leave a Reply

Your email address will not be published. Required fields are marked *