Winter 2000 Issue — Long-chain Omega 3 Fatty Acids
Essential Nutrients in Food

Per Gotfredson

BASF Health & Nutrition A/S

< Back

Introduction

Today there is a growing consciousness towards a healthier way of living including eating healthier foods. As a reflection on this trend a new type of foods and nutritional supplements have during the last decade occurred on the market more and more frequently. These type of products are all categorised by the fact that they contain an extra ingredient with a documented beneficial effect on the health, as for instance cereals enriched with vitamins and minerals or bread with extra fibres.

The newest trend in functional ingredients for use in food and nutritional supplements contains oils rich in long chained omega-3 fatty acids. During recent years a range of food products containing omega-3 fatty acids have penetrated the market and the products have become a success concurrent with the increased awareness of the nutritional value of omega-3 fatty acids. There has also been an increasing interest in addition of omega-3 fatty acids to special products such as infant formula and nutritional supplements for people with certain diseases.

Health benefits of omega-3 fatty acids

Long-chain omega-3 polyunsaturated acids from marine sources have been the substantial focus in the pursuit for means of lowering the risk of coronary heart disease (CHD) — one of the most common causes for death in tbe industrialised world. The interest in these nutrients started in the 70's when H.O. Bang and J. Dyerberg observed that Greenland Eskimos had a far lower risk of dying from CHD than members of Western populations. Investigations of the diet showed that the Eskimos had a very high intake of two specific long-chain omega 3 polyunsaturated acids — EPA & DHA — found in marine organisms only. Several studies have since confirmed that EPA & DHA can counteract the development of arteriosclerosis and thrombosis and thereby affect the risk of CHD. There is a consensus amongst nutritionists that the intake of long-chain polyunsaturated omega-3 fatty acids should be increased in order to meet the dietary requirements. It is sound sense to do this by incorporation of fish in the diet or through fortification of the diet with EPA & DHA.

Recommended daily intake of omega-3 fatty acids — EPA and DHA

Only a few countries today have officially implemented recommendations covering the intake of long-chain omega-3 fatty acids as a preventional precaution.

The Danish Ministry of Health recommends a daily intake of 35g fish of mixed species per day (lean and fatty), which corresponds to a daily intake of approximately 300mg EPA/DHA. The Committee on Medical Aspects of Food Policy in the UK recommends a weekly intake of l500mg of long-chain omega-3 fatty acids (EPA/DHA). This corresponds to a daily intake of approximately 215mg EPA/DHA.

The above recommendations, which should be seen as minimum preventive intakes in order to reduce the risk of suffering CHD, have a solid basis in a number of clinical studies.

Technical aspects in the fortification of food products with omega-3 fatty acids

There are often many problems concerned with eating pure oil rich in PolyUnsaturated Fatty Acids (PUFA) like omega-3 fatty acids or PUFA rich oil added to food products. The most evident problem is normally the bad taste and smell and not least the problems with development of oxidation products from the e.. In all cases where PUFA oils are consumed it therefore of significant importance that these oils do not turn rancid in the process of making the food. The rancidity results in the production of degradation products that are considered bad for the health, and it is also responsible for the development of bad taste and smell.

Due to the high content of long-chain omega-3 fatty acids in such oils it is thus necessary to protect these either by addition of antioxidants or through encapsulation in order to secure the stability. In many cases where long shelf life of the final product is required (i.e. infant formula), the addition of antioxidants to pure PUFA oil do not provide sufficient protection against oxidation. As many food products are exposed to high temperatures and air and humidity during processing, many attempts to add pure marine oils to food result in unstable products with a poor shelf life, which smell and taste badly. In best case only small amounts can be added before the taste of oil will change the taste of the food product. Therefore pure long-chain PUFA oils have a limited application in many food and nutritional products.

An alternative way of enriching foods without affecting the taste, odour or shelf life is the use of microencapsulated omega-3 fatty acids.

Microencapsulated polyunsaturated fatty acids

For the last fifteen years BASF Health & Nutrition has worked with development of oxidation stable, taste and odour neutral microencapsulated oil rich in long-chain omega-2 and omega-6 fatty acids for use in food products, infant formula, nutritional supplements and health products. This has resulted in the fact that today, by using microencapsulation technology it is possible to add stable PUFA rich oils to most food products without altering the shelf life or taste and odour of the chosen product. Microencapsulation results in a highly sophisticated powder where the oil is kept protected from degradation by the coating material used for encapsulation. During the microencapsulation process the oil is emulsified in an aqueous solution of coating agent and antioxidants, which is then finally dried. While drying the emulsion in a modified spray drying process, a layer of starch is added to the particles in order to prevent them from clutching together during the final drying in the fluid bed drier. During the whole microencapsulation process, the oxidation sensitive raw material is treated very gently in order to ensure the best quality. The result is an oxidation stable free-flowing powder that is taste and odour neutral when added to foods and other products.

The microencapsulated dry powder form has been tested in various foods including special nutritional supplements and it has proven to be stable for more than 2 years in products that require an increased shelf life, such as infant formula.

The technology of BASF Health & Nutrition A/S enables the addition of stable long-chain PUFA oils to a number of food products that have previously been precluded either because of smell and taste nuisance, or oxidation problems. In addition, the technology renders it possible to design the composition of omega-3 and omega-6 fatty acids and coating agents in such a way that the microencapsulated product fulfils requirements of fatty acid profile, solubility and coating material.

Application of omega-3 fatty acids in food products

Almost any food product can be enriched with omega-3 fatty acids and in most cases without altering the existing manufacturing process. In products with a high content of dry matter the microencapsulated form is normally used and for many applications it is the only form to use in order to ensure the stability of the food product. Some examples are: Bread, breakfast cereals, pasta, biscuits, cakes, milk powder and infant formula.

In products containing a lipid phase, omega-3 fatty acid has to be added in the natural oily form, whereas in products with a high content of water both the microencapsulated as well as the pure oily form can be used. In these types of food products with a high content of either lipid or water phase a number of precautions has to be taken against the risk of unpleasant taste and oxidation. The addition level is often more limited compared to the fortification of food products with a high content of dry matter, where the microencapsules are maintained intact during processing and storage. Furthermore additional antioxidants will be required as well as the requirement of the introduction of vacuum or nitrogen flushing during the process of the food product. The type of antioxidant depends on the legal situation. Typical food approved antioxidants will be tocopherol, ascorbyl palmitate, ascorbic acid or sodium ascorbate.

Today there are several product groups enriched with omega-3 fatty acids on the market. In Asia, where the fact that natural substances and ingredients have a positive impact on bealth has been known and recognised for centuries fortified products like bread, biscuits, beveraqes. noodles and milk based products and snacks has been successfully launched on the market. Also a lot of different products like bread. pasta. UHT milk, yogburt and soft drinks has recently been launched.

< Back