изомальт

Isomalt is an equimolar mixture of oc-D-glucopyranosyl-1,6- D-sorbitol (GPS) and α-D-glucopyranosyl-l,l-D-mannitol (GPM). The production process of isomalt involves two essential steps. In the first step, the 1,2 -glycosidic linkage between the glucose and the fructose moiety of sucrose is rearranged by an immobilized enzyme system to a 1,6 -glycosidic linkage, which is more stable and characteristic for the cross linkage in the amylopectin fraction of native starch. In the second step, the rearranged sucrose molecule, i.e., isomaltulose, is hydrogenated to the corresponding sugar alcohols. Isomalt is commercially available as a dry, white crystalline powder which is about half as sweet as sucrose.
In vitro studies with intestinal disaccharidases from mammals demonstrated that isomalt is cleaved much more slowly than sucrose or maltose. A slight inhibitory effect on maltose hydrolysis and on the active transport on glucose has also been observed.
Ingested isomalt is partly hydrolyzed in the small intestine and slowly absorbed in the form of glucose, sorbitol, and mannitol. The intact portion of isomalt, as well as some unabsorbed sorbitol and mannitol, reaches the distal parts of the gut where these products are fermented to volatile fatty acids.

Isomalt is a more or less equimolar mixture of 1-O-a-D-glucopyranosy-D-mannitol- dihydrate and 6-O-a-D-glucopyranosyl-D-sorbitol. Different production conditions, however, allow variations in the ratio of the two products. The solubility in water is about 24.5 % (w/w) at room temperature, but varies with the composition and increases with increasing temperature. In addition to the dry isomalt, a syrup is available.
Isomalt is, depending on the concentration, approximately 45–60 % as sweet as sucrose, stable under normal processing conditions of foods, and noncariogenic.
In the European Union, isomalt is approved as E 953 for a large number of food applications. It is GRAS in the United States and also approved in many other countries.
Owing to its low glycemic index, isomaltulose, an intermediate of the production, has found increasing interest as a food ingredient in recent years.

It is claimed that isomalt is odorless, white, crystalline, and sweet tasting without the accompanying taste or aftertaste. Sweetening power is from 0.45 to 0.6 that of sucrose. A synergistic effect is achieved when isomalt is combined with other artificial sweeteners and sugar substitutes. Principal applications are in confections, pan-coated goods, and chewing gum. The substance was approved for use in most European countries in 1985. Classification of isomalt as a GRAS substance was petitioned in the United States. (GRAS = generally regarded as safe.)

analgesic, NSAID

Isomalt is produced from food-grade sucrose in a two-stage process. Beet sugar is converted by enzymatic transglucosidation into the reducing disaccharide isomaltulose. This undergoes catalytical hydrogenation to produce isomalt.

Isomalt is a noncariogenic excipient used in a variety of pharmaceutical preparations including tablets or capsules, coatings, sachets, and suspensions, and in effervescent tablets. It can also be used in direct compression and wet granulation.
In buccal applications such as chewable tablets it is commonly used because of its negligible negative heat of solution, mild sweetness, and ‘mouth feel’. It is also used widely in lozenges, sugar-free chewing gum, and hard-boiled candies, and as a sweetening agent in confectionery for diabetics.

Isomalt is used in oral pharmaceutical formulations, confectionery, and food products. It is generally regarded as a nontoxic, nonallergenic, and nonirritant material.
Toxicological and metabolic studies on isomalt have been summarized in a WHO report prepared by the FAO/WHO Expert Committee (JECFA), resulting in an acceptable daily intake of ‘not specified’.
The glycosidic linkage between the mannitol or sorbitol moiety and the glucose moiety is very stable, limiting the hydrolysis and absorption of isomalt in the small intestine. There is no significant increase in the blood glucose level after oral intake, and glycemic response is very low, making isomalt suitable for diabetics. The majority of isomalt is fermented in the large intestine. In general, isomalt is tolerated very well, although excessive consumption may result in laxative effects.
Isomalt is not fermented by bacteria present in the mouth; therefore no significant amount of organic acid is produced that attacks tooth enamel.

Isomalt has very good thermal and chemical stability. When it is melted, no changes in the molecular structure are observed. It exhibits considerable resistance to acids and microbial influences. Isomalt is non-hygroscopic, and at 25°C does not significantly absorb additional water up to a relative humidity (RH) of 85%; paracetamol (acetaminophen) tablets based on isomalt were stored for 6 months at 85% RH at 20°C and retained their physical aspect.
If stored under normal ambient conditions, isomalt is chemically stable for many years. When it is stored in an unopened container at 20°C and 60% RH, a re-evaluation after 3 years is recommended.

GRAS listed. Accepted as a food additive in Europe.