Sugar esters
Sugar esters are esters of inorganic or organic acids with saccharides .
Occurrence
Some sugar esters of organic acids occur naturally. 6-Benzoyl-n-glucose (vaccinine) is found e.g. B. in blueberries and in the form of salicylic glucoside (populin) in various types of willow. An important group of naturally occurring sugar esters are also the tannins of the tanning group. In these, the n-glucose is esterified with gallic acid, digallic acid or also with ellagic acid.
Phosphoric acid esters such as fructose-6-phosphate play a key role in metabolism in both the animal and plant kingdoms . The sulfuric acid esters are also widespread in nature and are involved in the structure of naturally occurring polysaccharides, see e.g. B. Chondroitin . Carboxylic acid esters of fatty acids are represented in certain lipopolysaccharides .
Manufacturing
The sugar esters can generally be obtained by the action of the relevant acid halides in the presence of a suitable acid-binding agent (pyridine or quinoline). The chemical reaction results from fatty acid derivatives ( fatty acid methyl ester or fatty acid chlorides), and saccharides Zuckerester at various hydroxy groups of the saccharide. The desired esters are extracted from the resulting mixture and then purified.
For use in food, they are made from sucrose (simple table sugar ) and certain fatty acids (including stearic and palmitic acid ), which are mainly obtained from soy or other vegetable oils , but can also be of animal origin.
Properties and use
Synthetic carboxylic acid esters are used as surfactants and fatty acid esters are used, among other things, as emulsifiers in food.
Sugar esters of fatty acids
Zuckerester of fatty acids are used as emulsifiers or a flour treatment agent in baked goods ( cakes , puff pastry ), and including for confectionery , ice cream , alcoholic and non-alcoholic beverages (except beer and wine, as this specific legal provisions prohibit) and for the surface treatment of Used fruit .
They are very difficult to dissolve and have different emulsifying effects. They also influence the gelatinization properties of starchy foods. They make chocolate masses more flowable.
Fat substitutes , such as Olestra , are multiple esters of sucrose with fatty acids. The individual sucrose molecules are connected to several fatty acid residues via ester bonds. This is possible because sucrose molecules have several hydroxyl groups, each of which can then react with a fatty acid molecule during esterification. Such fat substitute products are practically calorie-free because they are indigestible and are eliminated from the body without being used.
If the doses are too high, sugar esters of fatty acids can have a laxative effect. The permitted daily dose is 40 mg / kg body weight in flavors for clear, flavored water-based drinks.
In the EU , sugar esters of fatty acids are permitted as food additives with the number E 473 .
Individual evidence
- ↑ a b c d e Josef Schormüller: The components of food . Springer-Verlag, 2013, ISBN 978-3-642-46011-1 , p. 416 ( limited preview in Google Book search).
- ↑ Horst Eierdanz: Perspectives on renewable raw materials in chemistry . John Wiley & Sons, 2008, ISBN 3-527-62473-2 , pp. 61 ( limited preview in Google Book search).
- ↑ Sugar esters of fatty acids: E 473, E473 - sugar esters of fatty acids , accessed on August 25, 2018.
- ↑ EU: REGULATION (EU) No. 818/2013 OF THE COMMISSION of August 28, 2013 , accessed on August 25, 2018.
- ↑ Werner Baltes, Reinhard Matissek: Food chemistry . Springer-Verlag, 2011, ISBN 978-3-642-16539-9 , pp. 235 ( limited preview in Google Book Search).