FREQUENTLY ASKED QUESTIONS ON PALM OIL

Palm oil is an edible vegetable oil extracted from the flesh, or mesocarp, of the oil palm fruit.

Crude palm oil is red in colour due to the high amount of natural carotenes found in the orange/red oil palm fruits.

Palm oil has a balanced fatty acid composition with an equal amount of saturated and unsaturated fatty acids. Its component fatty acids consist of approximately:

  • 50% saturated (mainly palmitic acid)
  • 40% monounsaturated (mainly oleic acid)
  • 10% polyunsaturated (mainly linoleic acid

Palm kernel oil is different from palm oil. It is extracted from the white kernel inside the palm fruit. Oil palms thus give two different kinds of oils from the same fruit, something very unique to an oil producing crop.

Palm kernel oil is naturally yellowish in colour and has a different fatty acid composition than palm oil. Approximately 82% of palm kernel oil is saturated fat with the main contributors being 48% lauric acid, 16% myristic acid, and 8% palmitic acid. Approximately 18% of palm kernel oil is unsaturated fat with 15% oleic acid (monounsaturates) and 3% linoleic acid (polyunsaturates).

Due to its high content of lauric acid, palm kernel oil is also called lauric oil. Another lauric oil, with similar composition to palm kernel oil, is coconut oil.

Coconut oil is at times confused with palm kernel oil, as its fatty acid composition is very similar to palm kernel, with a high amount of lauric acid.

Coconut oil is produced from the coconut milk which has been extracted from the coconut kernel. Cold pressed virgin coconut oil contains high amounts of Medium Chain Triglycerides, which are easily absorbed in the body. Although MCTs are classified as saturated fats, studies show that they do not have a negative effect on blood cholesterol.

It is known that saturated fats have a hypercholesterolemic (cholesterol raising) effect in blood plasma. And that palmitic acid, C16 present in palm oil (44%) being a saturated fatty acid, would have a similar effect upon human metabolism.

Substituting butter(having 66% saturated fatty acids-lauric and myristic) with palm oil resulted in decreasing levels in cholesterol.

Studies have shown that palmitic acid (given in the form of palm oil) have significant beneficial lowering effects on both total cholesterol and LDL cholesterol.

Studies have demonstrated that the impact of any dietary fatty acid on cholesterol levels in blood depends upon the chain length, relative saturation and relative concentration of all fatty acids available. Palm oil has a balanced composition of saturated (50%), and unsaturated fatty acids (50%). Palm oil should be classified as a partially–saturated fat. It does not behave metabolically as the classic saturated fats – it lowers and does not raise blood cholesterol levels.

No, like all other vegetable oils, palm oil as well as palm kernel and coconut oil are cholesterol-free. Cholesterol, which is a product of animal metabolism, is present in varying amounts in animal fats (eg. in butter, beef and eggs), but is virtually absent in oils and fats of vegetable origin.

There is a general misperception that because palm oil contains 50% of saturated fat, it must increase the cholesterol level in the body in the same way as other saturated fats such as the kind found in butter and meat. However, the composition of the saturated fat in palm oil is very different from that found in animal fats. The saturated fatty acids in palm oil consist of mainly palmitic and stearic acid, which are shown to have relatively neutral effect on blood cholesterol elevation. The monounsaturated portion of palm oil, consisting mainly of oleic acid, makes up about 40% and is easily digested and absorbed. Hence, palm oil does not raise blood cholesterol levels and is comparable to olive oil, which also contains large amounts of monunsaturates.

By nature, virgin, or crude palm oil is red in colour due to the natural content of carotenoids, also known as Vitamin A, found in the oil palm fruits.

Normally, crude palm oil undergoes a refining process whereby the carotenoids and thus the red colour is removed from the palm oil and the outcome is a yellow vegetable oil.

To obtain red palm oil, the crude palm oil instead undergoes a mild refining process using low heat and no bleaching. Hereby it is possible to retain the natural nutrients of carotenoids (along with Vitamin E) and the result is a vegetable oil with a beautiful red-golden colour, which is excellent for creative cooking and baking.

Oil palms are grown without genetic modification, hence palm oil is GMO-free. In Malaysia, plantation companies follow the strict agricultural regulations of the Malaysian Palm Oil Board, who guarantees that palm oil is 100% GMO-free, see certificate here.

Refining is the process whereby crude palm oil is converted to quality edible oil by removing moisture, free fatty acids and impurities from the crude oil. There are two ways of refining, namely alkaline and physical.

Alkaline refining, also known as chemical refining, uses caustic soda at the first stage to remove most of the free fatty acid present in the crude oil. It also removes gums, trace metals etc. This allows the refiner to deodorize the oil at lower temperatures which helps to retain more of the inherent tocopherols present in the crude, thereby making the chemically refined oil a more stable oil.

Physical refining uses excess phosphoric acid and bleaching earth to remove the gums, trace metals and other impurities (but not the FFA). The deodorization has to be carried out at a higher temperature to remove the large amount of free fatty acids. Tocopherols are lost at higher deodorization temperatures resulting in a less stable palm oil. High temperatures also cause the fatty acid group to undergo isomerisation and form trans fatty acids.

Refined palm oil is semi-solid at room temperature with a melting profile close to butter fat. Due to its low level of polyunsaturated fatty acids, it has good resistance to oxidation and heat making it ideal as a frying oil not only in households but especially in the food manufacturing industry, where it is used in the production of eg. instant noodles, french fries, potato chips and snacks.

In food uses, palm oil can be used to produce a variety of products such as shortenings, margarine, cooking oil, confectionery and speciality fats and it is incorporated into products such as coffee creamers, ice cream and bakery products.

In non-food uses, palm oil is found in products such as soaps, detergent, cosmetics and candles.

Palm kernel oil differs significantly from palm oil in both composition and properties. Palm kernel oil is a lauric oil which resembles coconut oil. It is solid below 20 Deg. C, but above it melts rapidly. This sharp melting profile makes it ideal in the production of confectionery applications where it can substitute cocoa butter. Palm kernel oil is also used as a frying medium and in the manufacturing of margarine.

Fractionation is the process whereby refined palm oil or palm kernel oil is separated into two products, namely liquid palm olein and solid palm stearin. The fractionation process involves cooling of the palm oil under controlled conditions to low temperatures, followed by filtration of the crystals through a membrane press to separate the solid from the liquid part of the oil. Each fraction can be further fractionated to make products with various applications

Hydrogenation is the process of hardening oils or fats by adding hydrogen to the double bonds of unsaturated acids in the fat molecule. Hydrogenation is widely used in the food manufacturing industry to convert unsaturated fats and oils into harder forms which are more suitable for food applications such as margarines and shortenings. Furthermore, highly unsaturated oils are susceptible to oxidation, which deteriorates the oil quality and turns the oil rancid. By hydrogenation, the oxidative stability of unsaturated oils is improved. A disadvantage of the hydrogenation of soft oils is the formation of trans-fats.

Palm oil has a liquid (olein) and a solid (stearin) fraction, which can be seen if you leave the oil at room temperature below 25 Deg C. The fact that palm oil consists of both fractions is a big advantage over other oils: The solid fat fraction can be used directly in many applications without the need for hydrogenation and thus being trans-free.

Generally, the lower the Iodene Value, IV (lower level of unsaturated fatty acids) of the oil, the more suitable it is for frying. An exception are coconut and palm kernel oils having short chain fatty acids which are volatile and have low smoke point. The lower the IV of the palm olein, the more stable and resistant it is to oxidation at high temperatures.

The disadvantage of hydrogenation is that not all the polyunsaturated acids are converted into the desired less unsaturated and saturated acids. Instead, they form trans fatty acids (TFA), which research shows are damaging to health. Trans-fats have a negative impact on blood cholesterol and have been linked with the risk of heart disease.

Frying is usually performed at 180 Deg. C and a fat used for frying must thus be able to withstand these high temperatures without risk of adverse chemical changes in the oil. For suitability of oil for frying, we have to consider the inherent stability to oxidation. Inherent stability relates to the extent and type of unsaturation of the fatty acids in the oil and their relative reaction rate with oxygen. In general the rate of reaction during frying with fats obey the following sequence, Polyunsaturates (PUFA) > Monounsaturates (MUFA)> Saturates (SA). In short the greater its unsaturation, the poorer their stability.

Oxidation further generates secondary reactions where polyunsaturated fats containing C18:2 & C18:3 form polymers at high temperatures. This property is conferred by the reactive sites of double bonds on a fat molecule.

Soya, Sunflower, corn oils are unsuitable as frying oils as they contain more unsaturates. The unsaturates here are predominantly made up of PUFA and lesser of MUFA, a property that further disadvantages it as a frying medium, (except if they are hydrogenated to reduce the unsaturation in which case trans fatty acids are formed). Olive and Palm Oil on the contrary possess higher MUFA and hence behave better during frying. However,the former succumbs to the latter in this respect with its more stable (palm) saturates. Generally, the lower the Iodine Value, IV (lower level of unsaturated fatty acids) of the oil, the more suitable it is for frying. The lower the IV of the palm olein, the more stable and resistant it is to oxidation at high temperatures.

Other advantages using palm olein for frying:

a) Palm oleins with lower C18,3 (linoleic acid) content does not leave an unpleasant oily odour in the kitchen unlike soya, sunflower oils.

b) With the higher melting point, there is less emission of oily fumes with condensation and deposition on walls and ceilings unlike the soft oils.

c) Less polymer formation when palm oleins are used. Polymerisation gives the food an off flavour and taste. The fried food would also turn rancid faster.


Sources:

  • americanpalmoil.com
  • Dr Augustine S.H: Ong and Dr S.H: Goh. Palm Oil – The Preferred Partner in the Food Manufacturing Industry. Palm Oil As Healthy as Olive Oil, March 2002
  • Ministry of Plantation Industries and Commodities Malaysia, Pocketbook of Palm Oil Uses, 2009
  • mpoc.org.my
  • poram.org.my

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