FAQ
A fat consists of triglycerides. One fat molecule, a triglyceride, is an ester that is formed from a molecule of glycerol coupled with three fatty acids. There are two types of these fatty acids: saturated and unsaturated fatty acids. Unsaturated fatty acids can be divided into the monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). Mono refers to the presence of just one double bond in the chemical structure of the fat, while poly means that more than one such bond is present. Unsaturated fatty acids can occur as the cis-variant and the trans-variant, although in practice when unsaturated fatty acids are referred to, only the cis-variants are meant. Trans-unsaturated fatty acids are usually referred to just as trans fatty acids.
Fats fulfil an important function in many food products:
A certain degree of hardness of the fat is often needed for this. This hardness is needed for the structure and the stiffness. In the past fats with the desired degree of hardness were often saturated fatty acids and/or trans fatty acids. Fortunately, innovations in the oils and fats sector have made it increasingly easier to produce food products using healthy fats that still have the desired taste, texture and shelf life.
- fats give sensory satiety
- fats are important taste components
- fats make certain methods of food preparation possible, such as deep-frying and normal frying
- fats play a part in the transfer of heat and in the water activity of a product
- fats help to determine the consistency, the texture, the feel in the mouth and the melting behaviour
A certain degree of hardness of the fat is often needed for this. This hardness is needed for the structure and the stiffness. In the past fats with the desired degree of hardness were often saturated fatty acids and/or trans fatty acids. Fortunately, innovations in the oils and fats sector have made it increasingly easier to produce food products using healthy fats that still have the desired taste, texture and shelf life.
A fatty acid that is labelled as C18:2 (linoleic acid) stands for a fatty acid with 18 carbon atoms and 2 unsaturated bonds. This is an omega-6 fatty acid (or n-6 fatty acid), this means that the double bond is situated at the 6th carbon atom from the methyl group (-CH3). As well as this notation a so-called delta-notation (Δ) is also used in which the carbon atoms are counted from the opposite end of the fatty acid, that is from the -COOH group.
The body needs fats every day. A healthy diet provides between twenty and forty percent of the daily calories as fat. Fats are an important source of the vitamins A, D and E and essential fatty acids.
Saturated and unsaturated fatty acids can occur in both animal and vegetable fats. As a general rule, the softer the fat the better it is. Many vegetable oils are unsaturated to a large extent, that is they are rich in the good unsaturated fatty acids.
The definition of a trans fatty acid is an unsaturated fatty acid with a double bond in the trans configuration (that is that for one or more of the double bonds the two hydrogen atoms are situated in opposite directions to each other around the double bond). Apart from this similarity, trans fatty acids can differ from each other in the chain length, in the number of double bonds and in the positions of the double bonds.
Trans fatty acids can be formed when oils are partially hardened and in the digestive channel of cows and sheep. A large part of the isomers that can occur are present in both animal and vegetable products. In the past it has been shown that trans fatty acids are bad for health because they increase LDL cholesterol. Hereby it has not been found that there is a difference between trans fatty acids from animal or vegetable origins. As well as this there is no good hypothesis about a working mechanism in which the effects of animal or vegetable trans fatty acids may be different.
Research carried out in 2003 by Mensink et al. showed that unsaturated fatty acids are better for the cholesterol level than saturated fatty acids. Unsaturated fatty acids increase the HDL cholesterol and lower the LDL cholesterol. Saturated fatty acids in contrast increase both LDL and HDL cholesterol. Some saturated fatty acids appear to be less bad than others in this, but more research is necessary to determine this definitely. Until this has been carried out the Netherlands Health Council is staying with the advice to replace saturated fatty acids in the intake of food as far as possible with unsaturated fatty acids.
That is no problem. Hardening or hydrogenating is a technique that is used to change the consistency of a fat and to increase the stability to heat or oxidation. In this process hydrogen atoms are added to the unsaturated, double bonds in the fatty acids with the help of a catalyst. In the past high concentrations of trans fatty acids were formed during the partial hardening of a vegetable oil to a vegetable fat. New technologies make it possible, however, to have hardly any trans fatty acids formed during the process. When oils are fully hardened then no trans fatty acids are formed at all. At the same time it is a fact that a fat with a certain degree of hardness is still required for a particular functionality for many food products. Several techniques are available to the oils and fats sector for producing fats with the desired functionality and hardness but with an improved fatty acid composition. One of these techniques is hydrogenation. Fat mixtures containing hardened fats can in a number of cases have a better fatty acid composition for the same functionality than fat mixtures without hardened fats. It is for this reason that the Product Board MVO is lobbying for mandatory nutrition labelling of the amount of trans fatty acids and saturated fatty acid, in contrast to the mandatory labelling of the terms hydrogenated or hardened. What after all is important is the fatty acid composition of a product (as little as possible saturated fatty acids and trans fatty acids, and as much as possible unsaturated fatty acids) and not the techniques that have been used to produce this optimum ratio.
Yes, unsaturated fats are healthy and should therefore be used in products. It can happen, though, that the functionality of a product with a large amount of unsaturated fat is different in some cases. Oils with a large amount of saturated fatty acids and trans fatty acids are more stable than unsaturated fatty acids and melt at a different temperature. Within the group of unsaturated fatty acids monounsaturated fatty acids are more stable than polyunsaturated fatty acids. By modifying an oil (for example, by interesterification or fractionating) it is possible to improve the fatty acid composition and at the same time gear this to characteristics such as the melting behaviour and stability.
As well as this, more and more raw materials are coming onto the market with an optimised fatty acid composition. An example of this is an oil with a higher oleic acid content and a lower content of linoleic and linolenic acids. This composition gives the end product a longer shelf life or increased stability.
As well as this, more and more raw materials are coming onto the market with an optimised fatty acid composition. An example of this is an oil with a higher oleic acid content and a lower content of linoleic and linolenic acids. This composition gives the end product a longer shelf life or increased stability.
Omega-3 fatty acids are thought to be effective for a large number of afflictions but many of the effects have still not been proven. There are many strong indications that an increased intake of long chain omega-3 fatty acids reduces the risk of fatal coronary heart diseases. For instance, an Italian GISSI study (Lancet 1999) showed that the percentage of sudden death in people who had already had a heart attack dropped by 45% by the use of omega-3 supplements. As well as this, the total mortality rate dropped by 20% and the deaths due to cardiovascular diseases by 35% after taking omega-3 fatty acid supplements. There are also studies that show that omega-3 fatty acids have a beneficial effect in patients suffering from rheumatoid arthritis, osteoporosis and certain chronic inflammation diseases (for example, Crohn’s disease). Omega-3 fatty acids have also been related to ADHD, dyslexia and Alzheimer’s disease.
Just like all other products butter is suitable for use in a good diet so long as there is sufficient variation within that diet. Butter is particularly valued because of its specific taste. The nutritional value is, however, less than that of a margarine. In comparison to margarine butter has more saturated fatty acids and more trans fatty acids. Nowadays there are products on the market that combine the good taste of butter with the good fatty acid composition of vegetable oils.
