Function and application of phytosterol esters

Plant sterol ester properties

Phytosterol esters are generally made from phytosterols with fatty acids by esterification or transesterification reactions. 

Since there are more species of both sterols and fatty acids that can be used to make plant sterol esters, a variety of plant sterol esters of different physicochemical properties are available, with the three major plant sterol esters being β－ Sitosterol esters, stigmasterol esters, campesterol esters. 

Sterol esters are able to be converted into sterols and fatty acids in humans, so their physiological functions include those carried out by both parts of phytosterols and fatty acids, with the effect of reducing plasma total cholesterol and LDL cholesterol to the same extent as free phytosterols, and in some respects even better.

Phytosterols in the form of crystals have problems in applications in the following two ways, on the one hand, the solubility and bioavailability of the crystalline form in humans are relatively poor, thus leading to a high dose in the treatment of hyperlipidemia and the resulting hyper phytosterolemia, ie, markedly elevated phytosterol concentrations in the serum. 

On the other hand, the solubility of phytosterols in oils is small, causing difficulties for application in food products.

Phytosterols have a significant hypolipidemic function, which has been confirmed by numerous studies. However, phytosterols are insoluble in water and have rather limited solubility in the oil phase, a drawback that limits their applications. 

For many years, attempts have been made to modify plant sterols to expand their applications. Foreign countries have begun to explore the routes of plant sterol applications since the early 1990s, and many kinds of plant sterol products have been developed through purification and modification of hexane. 

Among them esterification of plant sterols to sterol esters is one of the most important means of modification. Sterol esters of esterified products as hypolipidemic functional factors can be widely used in products such as margarine, applied oils and ice cream, while reducing the use of emulsifiers. 

The fact that phytosterol esters can be added in most food products to improve nutritional value without affecting the texture of food specimens greatly expands the application scope of phytosterol esters.

To facilitate the application in food processing, it is required to change the form of plant sterols without affecting the physiological functions of plant sterols.

 Whereas plant sterol fatty acid esters meet this requirement, it greatly improves the lipid solubility of plant sterols so that they can be added to foods containing oil.

 Plant sterol esters are absorbed by hydrolysis by pancreatic cholesterol lipase into free type sterols, which is the only difference between free sterols and ester type sterols in metabolism, so that plant sterol esters have the same physiological function as plant sterols.

Regulatory changes in sterol ester use

The safety of plant sterol esters has been recognized in several countries and regions of the world, including our country. 

In 1999, the US Food and Drug Administration (FDA) granted "" good health "" labeling for foods with added phytosterols and esters. 

In 2000, a health announcement issued by the US FDA stated the following: "" phytosterols and esters, phytosterols and esters, can help reduce the risk of coronary heart disease by reducing the level of cholesterol in the blood. A daily intake of 1.3g phytosterol or 3.4g phytosterol from your diet can achieve a significant cholesterol lowering effect "".

In February 2003, the US FDA approved the Cargill company health claim of plant sterols being beneficial to heart health, officially giving the plant sterol market "" legal status "".

In 1999, the Ministry of agriculture and forestry of Japan also approved phytosterols, plant sterol esters, phytostanols, and phytostanol esters as functional additives to FOSHU, a specific specialized health food that regulates blood lipids.

In 2004, the European Commission approved the use of phytosterols and plant sterol esters in several specific food categories, such as butter coatings, milk based products, and buttermilk based products. In February 2007, the UK Food Standards Agency granted approval for phytosterol health ingredients while complying with the EU regulation on novel foods.

In 2010, our country allowed the use of phytosterol esters as new resource foods in food added to the Ministry of health's notice on the approval of seven items such as DHA algal oil, cottonseed oligosaccharides as new resource foods and other related regulations (No. 3, 2010).

Application

Applications since phytosterols have significant hypolipidemic functions, they are widely used in health products. It can also be used in foods for special populations or in foods for middle-aged and older people. Not to be applied in infant food.