Plant Sterols (Phytosteroles)

Description

Plant sterols (phytosteroles) are secondary plant components. They occur primarily in the fatty parts of plants as oils, nuts and seeds.

Phytosteroles exhibit a chemical structure that closely resembles that of cholesterol. Through a specific mechanism, they lower the absorbtion of cholesterol into the blood stream in the small intestine. The body then resorts to its own reserves and the cholesterol level decreases.

Phytosteroles are considered novel foods and must pass an approval procedure before they are placed on the market. An approval has been issued for a multitude of products including diet margarine and yoghurt.

Application

Plant steroles, stanoles (saturated derivates of steroles) and their esters generally have a great health promoting effect. Not only do they lower the cholesterol level but also are assumed to be preventative to colon cancer. Therefore, they are used in a multitude of novel foods. Examples are:

• fat spreads, such as margarine, that are assumed to lower the cholesterol level by up to ten per cent.
• milk products, such as yoghurt and cheese
• salad sauces, seasoning sauces
• beverages, such as soy milk

The application for approval has been made for the following products: grain products, rice drink, fruit juice, sausage and meat products, baking goods, plant concentrates.

Consumption should not exceed 3g per day and an overdose is a matter of concern for health. There are indications that phytosteroles also affect the absorption of fat-soluble vitamins and pro-vitamin A.

Gene technology

Plant steroles are primarily won from oleiferous plants, especially soybeans.
In the first step, crude oil won from soybeans is refined. At the end of this process, the interfering taste- and aromatic substances that remain are removed (in a process known as deodorisation). Subsequently, an extract is gathered, from which phytosteroles may be isolated after purification and processing. For esterification, fatty acids or tryglycerides are used. Esters are saturated compounds and hence have a higher fat solubility.

• Soy beans: internationally handled raw materials from soy beans generally are derived partly or wholly from genetically modified plants. GM soy beans are cultivated extensively in Argentina and the USA. The EU obtains a large part of soy raw material from these countries.
• Several food corporations exclusively process conventional soy raw materials. The absolute separation of conventional and GM soy beans in all processing stages is technically imossible. Therefore, even raw materials declared to be "gene technology free" may contain minor proportions of GMO. These proportions may be as much as 0.9 per cent.

Labelling: phytosteroles obtained from GM plants (soybeans) are subject to a labelling requirement. Coincidental, technically unavoidable GMO admixtures of as much as 0.9 per cent in raw materials from soy beans are not subject to a labelling requirement in the foods produced thereof.