COST research action on multidisciplinary hen egg research

Brussels, 15 April 2002

Memorandum of Understanding for the implementation of a concerted European research action designated as COST Action 923 "Multidisciplinary Hen Egg Research." European Cooperation in the field of Scientific and Technical Research - COST Secretariat. Brussels, 12 April 2002 (document COST 231/02). Full text

Delegations will find attached hereto the text of the abovementioned Memorandum, signed in Brussels on March 2002 by Austria, Finland and France, on 8 April 2002 by Italy and on 10 April 2002 by Greece.

The Signatories to this Memorandum of Understanding, declaring their common intention to participate in the concerted Action referred to above and described in the Technical Annex to the Memorandum, have reached the following understanding:

1. The Action will be carried out in accordance with the provisions of document COST 400/01 "Rules and Procedures for Implementing COST Actions", the contents of which are fully known by the Signatories.

2. The main objective of the Action is to find new uses of hen egg in order to exploit the outputs even beyond the traditional food value of eggs, including biomedicals, nutraceuticals and ovo-biotechnologies.

3. The overall cost of the activities carried out under the Action has been estimated, on the basis of information available during the planning of the Action, at EURO 20 million in 2001 prices.

4. The Memorandum of Understanding will take effect on being signed by at least five Signatories.

5. The Memorandum of Understanding will remain in force for a period of four years, unless the duration of the Action is modified according to the provisions of Chapter 6 of the document referred to in Point 1 above.

A. BACKGROUND

The role of the hen egg in the human nutrition is decisively essential. Eggs are nutritious and healthy, the biological value of both albumen and yolk is high, and the eggshell provides an excellent barrier against both chemical and biological attacks. Hen eggs have been an important nutrient source for mankind for thousands of years. Still the total potentiality of the eggs has not been discovered yet.

According to a recent report of American College of Nutrition, there is a tendency in the United States to loosen the dietary restrictions concerning the consumption of eggs, because in the eggs there are many nutritious components healthy for humans, and only one major disadvantageous one, as discussed below. In the report a question is raised also about prospects to use eggs or their components as functional food ingredients. These ideas were also the basis for preparing this COST Action.

Egg white, also called albumen, is a viscous 10% solution of proteins and peptides and minerals in water. These proteins are highly nutritive for humans by their amino acids composition, which has been noted several decades ago. In addition, the egg albumen has unique functional properties in food systems, such as stabile foam production. Later it has been noticed that the components of the albumen possess micro-biocidal and other new functional properties. There are several research groups presently working in this area, both to explain the structure-function relations and to find separation methods to isolate active moieties, proteins and peptides, from the albumen mixture. In addition to the membranes formed by the albumen proteins, there are several protein containing membranes next to the eggshell, which are called vitellins. They probably have several different properties, which shield the hen embryo, however, these proteins may have useful new functions outside the food production branch as well.

Egg yolk is more fatty part of the hen egg. The water content is about 50%, and from the remainder 1/3 is protein and 2/3 fat and fat-soluble constituents. The protein part is differing from the albumen, still research work is going on to study its functionality both in foods and other biological systems. Main adverse effect of hen eggs as food has been laid on its content of cholesterol.

According to the present knowledge the intake of saturated fat rather than intake of cholesterol is increasing the cholesterol bodies content in the bloodstream. Partly due to this several studies have been conducted to change the fatty acid composition of hen egg yolk to more unsaturated direction, that is, to increase omega-3 fatty acid content. Also the ratio of omega-6/omega-3 in western diet might need adjustment to more healthy directions, i.e. 10/1 ­ 5/1.

It is well documented that the fatty acid composition of hen egg yolk can be modified through alterations in the diet. Feeding with sources rich in long-chain omega-3-fatty acids increases the content of these fatty acids in egg yolk. Eggs can, therefore, be an alternative to fish and oilseeds as a source of omega-3-fatty acids. Modification of the fatty acid content of hen eggs often causes organoleptic problems. A flaxseed-based diet has been found to give a fishy aroma to the egg. It is important that the modification of the hens' diet does not affect the functional properties of eggs, particularly when the eggs are processed for food products, for example in a bakery.

In addition to the above mentioned research, studies on the effect of feed on the fat-soluble vitamin content of eggs are recently started. The addition of vitamins to hen feed may have more effects on hens than do the modification of fat source, however, short term feeding trials do not seem to affect on the health of the hens. Long term feeding studies are going on in some research institutes.

Only a few studies concerning the possible effect of the modified lipid composition to foaming properties of eggs have been done. Differences in volumes of sponge cakes made with eggs from hens of the oil-supplemented trial groups were estimated, but the practical significance of these differences is considered very low. In the literature there is no conclusive evidence, that various levels of rape-seed, included in the diet of laying hens, influence the foaming properties of hen eggs. Some publications report no significant influences on the foaming properties of egg albumen, whereas others report differences in foam formation of eggs for both albumen and whole egg.

Hen eggs are considered a chemical storehouse composed of various chemical compounds that form the basis of life. Egg yolk phospholipids, bioactive protein components, vitamins and carbohydrate moieties are reported to be important factors of many biologically important reactions in life. Many of the egg albumen proteins are glycoderivatives. The sugar chains of these glycoproteins seem to have several important physiological functions in living cells. Moreover, even the eggshell membranes and other by-products are under continuous investigation due to their biological importance.

Recently, egg researchers all over the world have noticed the possibility to combine traditional egg research with modern biotechnology and separation techniques. For example, the egg components can be fractionated and used for different food and non-food purposes. Egg albumen and egg yolk are studied both to find new innovative ways to use their components and to find new ways to modify their composition.

There are networks of egg researchers in Europe, mainly organised by the World's Poultry Science Association, but they are concentrating more on traditional egg research. In previous and ongoing COST Actions relevant to the hen egg research, research topics such as egg production hygiene, animal diseases and overall animal welfare have been discussed (i.e. COST Actions 97, 839, 840 and 846). This COST Action complements existing COST Actions and by co-operation all Actions will benefit.

In Finland a national network called HiTechEgg Research Program was founded in 1997. In this program all the Finnish egg research experts and their projects were collected under the same umbrella. The main task of this national network is to combine the knowledge in this field of technology to produce egg products and fractions (both from albumen and yolk) which may enhance health by providing physiological benefits for human health. So called modified eggs, albumen ovomucin and yolk phospholipids are examples of these new products. A very interesting application is also the use of ImmunoglobulinYs for treating fish diseases. The experiences from this network are very promising and especially the interest the industry has shown in the program is encouraging.

The international network formed with the this COST Action is vital for the egg research in Europe, because when the new ways to use the eggs are developed the problem of overproduction is solved without cutting down the production. The production of hen eggs is an important part of the agriculture production in the European Union Member States as well as in the Non-EU member states....

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