Stability of oils and fats

By Robert Griffiths, RSSL

There are many oils and fats that have great potential as functional ingredients and nutritional supplements, omega-3 oils being the most obvious example. More generally, oils and fats are necessary ingredients in many food products or in cooking processes. Moreover, there are fat containing foods, such as margarines, which are often used as carriers for other functional ingredients, as in the case of the cholesterol-reducing spreads that contain sterols.

Although some fats have received negative publicity, it is far from the case that all fats are bad. Indeed there are many fats that are necessary for health, and there are many products that exploit our dietary requirement for the essential fatty acids i.e. those that the body cannot produce for itself.

However, whilst many oils and fats are desirable, they also often have the undesirable characteristic of being prone to oxidation. Oxidation is essentially a series of chemical reactions involving oxygen that degrades their quality and eventually produces rancidity, with accompanying off flavours and odours.

Any product that contains oil or fat can be affected by this problem, and every attempt must be made to understand whether instability is an issue for a particular product, and what can be done to arrest the oxidation process, both during manufacture and afterwards during distribution and final storage by the consumer. Indeed, manufacturers may wish to work with suppliers to reduce oxidation during actual production of the oil and fat raw materials to ensure these are of the optimum quality for their product.

This article is available in full in the Winter 2014 issue of Nutraceuticals Now