Linoleic Acid

Linoleic Acid
Linoleic Acid (also called cis,cis,-9,12-octadecadienoic acid) is an example of a poly-unsaturated fatty acid, due to the presence of two C=C double bonds. It is the main fatty acid found in vegetable oils such as soybean oil, corn oil and rapeseed oil.

It is used for manufacturing margarine, shortening, and salad and cooking oils, as well as soaps, emulsifiers, and quick-drying oils. The word linoleic comes from the Greek word linon (flax), and oleic meaning relating to or derived from oil.

Essential Fatty Acids
Linoleic acid belongs to one of the two classes of essential fatty acids that humans require. These acids are called "essential" because they can not be synthesised by the human body and must be eaten in food. If a person does not eat sufficient amounts of these essental fatty acid (i.e. at least a tablespoon day), they may start to suffer symptoms including dry hair, hair loss, and poor wound healing.

The two families of EFAs are ω-3 (or omega-3 or n-3) which comes from fish oils, and ω-6 (omega 6, n-6) which come from vegetable oils (linoleic acid is one of these). When they were discovered to be essential nutrients in 1923, the 2 families of essential fatty acids were designated as 'Vitamin F'. But around 1930, it was realized that they are better classified with the fats than with the vitamins, and so the name Vitamin F was dropped.

Margarine
In order to convert the liquid linoleic oil (and its triglyceride) into soft solid margarine, hydrogen is bubbled through the oil in the presence of a nickel catalyst under fairly mild conditions (175-190°C, 20-40 p.s.i.).

Hydrogenation in this way does a number of things. Firstly, hydrogen attaches to some of the double-bonded carbons, increasing the saturation level. In doing so, the molecules lose some of the rigidity associated with double bonds and so are able to flex. This allows them to pack closer together, raising the melting point, and turning the oil into a solid fat.

The removal of some of the reactive double bonds in this way also reduces the chances of attack by oxygen, so that the fat becomes rancid much less readily, increasing its shelf-life. Superheated steam is then passed through the molten fat to remove any impurities (especially bad-smelling acids and aldehydes).

But since this process also removes the coloration from the fat, artificial colouring agents made from carotenes of various kinds are added to make it appear yellow and buttery. Other additives include butanedione (to make it smell like butter), vitamins A and D, emulsifiers (to sharpen the flavour) and binding agents (lecithins) to hold the whole thing together.
Linoleic Acid

Palm Oil and Vitamin E

Palm Oil and Vitamin E
Palm oil is a good source of vitamin E. A fat-soluble vitamin, vitamin E is an essential micronutrient for humans and consists of two series of compounds - tocopherols and tocotrienols.

Both are characterized by a side chain which is saturated in the tocopherols, but unsaturated in the tocotrienols.

Although tocopherols occur in several vegetable oils, palm oil represents one of the richest, natural sources of tocotrienols, which are also present in rice bran and barley.

The Vitamin E in palm oil is a mixture of different tocopherols (18-22%) and tocotrienols (78-82%). Alpha and gamma tocopherol each account for about 35% of total tocopherols, while gamma tocopherol accounts for about 10%.

Amongst the tocotrienols, the major ones are gamma tocotrienol (46%), alpha tocotrienol (22%) and delta tocotrienol (12%).

Recently, palm oil-derived tocotrienols have been extensively studied for their antioxidant capabilities, anti-cancer properties (for which there is strong supportive scientific evidence), as well as their ability to influence cholesterol metabolism.

Although some of the earlier studies suggested that supplementation with tocotrienols lowered cholesterol by affecting endogenous synthesis, a recent study noted no effect.

This may in part be due to the fact that it is not yet resolved which of the tocotrienol isomers are involved.
Palm Oil and Vitamin E

Vitamin E

Vitamin E
Vitamin E is a fat-soluble vitamin that exists in eight different forms. Each form has its own biological activity, the measure of potency or functional use in the body.

Alpha-tocopherol is the most active form of vitamin E in humans, and is a powerful biological antioxidant.

Antioxidants such as vitamin E act to protect your cells against the effects of free radicals, which are potentially damaging by-products of the body's metabolism.

Free radicals can cause cell damage that may contribute to the development of cardiovascular disease and cancer.

Studies are underway to determine whether vitamin E might help prevent or delay the development of those chronic diseases.

Vegetable oils, nuts, and green leafy vegetables are the main dietary sources of vitamin E. Fortified cereals are also an important source of vitamin E in the United States.
Vitamin E