Isomaltulose is a disaccharide carbohydrate composed of glucose and fructose. The glucose and fructose are linked by an alpha-1,6-glycosidic bond (chemical name: 6-0-?-D-glucopyranosyl-D-fructose). Isomaltulose is present in honey and sugarcane extracts. It tastes similar to sucrose (table sugar) with half the sweetness. Isomaltulose is also known by the trade name Palatinose, which is manufactured by enzymatic rearrangement (isomerization) of sucrose from beet sugar. The enzyme and its source were discovered in Germany in 1950, and since then its physiological role and physical properties have been studied extensively. isomaltulose has been used as an alternative to sugar in foods in Japan since 1985, in the EU since 2005, in the US since 2006, and in Australia and New Zealand since 2007, besides other countries worldwide. Analytical methods for characterization and assay of commercial isomaltulose are laid down, for example, in the Food Chemicals Codex. Its physical properties closely resemble those of sucrose, making it easy to use in existing recipes and processes.
Isomaltulose is hydrogenated to produce isomalt, a minimally digestible carbohydrate that like dietary fiber is fermented in the large intestine or colon to short-chain fatty acids. Isomalt is used as a sugar replacer, for example in sugar-free candies and confectionery.
Like sucrose, isomaltulose can be digested to glucose and fructose. However, while in sucrose the glucose is linked to the anomeric carbon of the fructose (an ?-1,2 linkage), in isomaltulose the linkage is to the 6 carbon (?-1,6), making isomaltulose a reducing sugar, unlike sucrose. The fructose in isomaltulose exists in a ring structure that readily opens to exhibit a carbonyl group as in ketones and aldehydes, which explains why isomaltulose is a reducing sugar. In comparison with sucrose and most other carbohydrates, isomaltulose is not a significant substrate for oral bacteria. Consequently acid production from isomaltulose in the mouth is too slow to promote tooth decay).
Video Isomaltulose
Function
In nutrition, isomaltulose is a source of food energy. It provides the same amount of energy as does sucrose. The energy from both isomaltulose and sucrose is used to fuel physical, mental, physiological and metabolic activities. By way of the heat release during fueling these activities both sucrose and isomaltulose help to keep the body warm. In foods, both isomaltulose and sucrose are sweeteners. Isomalt is less sweet than sucrose.. In food preparation and processing, both isomaltulose and sucrose have similar characteristics allowing recipes that use sucrose able to use isomaltulose instead or together.
Available carbohydrate
Isomaltulose is an available carbohydrate like sucrose and most others sugars or maltodextrins. Available or "nutritive" carbohydrates serve the body as a source of energy for its physiological functions. Whether a carbohydrate becomes available to the body largely depends on its digestion, absorption, and metabolism,
- A carbohydrate that is absorbed (with or without prior digestion) and is fully metabolized in humans (i.e. is not excreted into urine) is known to nutritionists as 'available carbohydrate'.
When present in foods and beverages that are ingested by humans, isomaltulose is digested completely and absorbed. Its intestinal digestion involves the enzyme isomaltase, which is located at the surface of the brush border lining the inner wall of the small intestine. This enzyme is otherwise involved in the digestion of ?-1,6 linkages present in starch. The products of isomaltulose digestion are glucose and fructose, which are absorbed and enter blood. Once absorbed, the glucose and fructose follow the same metabolic pathways through the body as if they were derived from sucrose. While fructose is mostly converted to glucose or glycogen stores in the liver, glucose from the small intestine and liver is distributed via blood to different parts of the body where it serves cellular metabolism as an energy source directly or indirectly after storage as glycogen in the tissues of the body especially in skeletal muscle.
Source of energy
Based on the heat released on complete burning of isomaltulose in oxygen to carbon dioxide and water, and its categorization as availability of carbohydrate, the food energy value of isomaltulose is identical to that of sucrose. For both, it is 4 kcal/g (17 kJ/g), a value that is used in food labelling or dietary planning.
Slow and sustained release of carbohydrate and energy
Isomaltulose is slow to be digested, absorbed and so is released as glucose and fructose into the bloodstream gradually . After ingestion, the enzymatic digestion of sucrose and isomaltulose occur on the same sucrase-isomaltase enzyme complex, which is located in the small intestine. Several studies show that this complex breaks down isomaltulose slowly compared to sucrose. The maximum rate at which an enzyme can use a substrate is known as the Vmax. The Vmax of isomaltase for isomaltulose is 4.5 times slower than that of sucrase for sucrose.
As a result of its slow digestion, isomaltulose reaches more distally in the human small intestine than does sucrose, as evidenced by their different incretin hormones responses. The incretin hormone glucose-dependent insulinotropic polypeptide (GIP) is secreted from the earlier (proximal) part of the small intestine in lower amounts after isomaltulose than for sucrose ingestion, whereas the incretin hormone glucagon-like peptide-1 (GLP-1) is secreted from a later (distal) part of the small intestine in higher amounts with isomaltulose compared with sucrose.
Compared with sucrose, the absorption of energy as carbohydrate from isomaltulose is prolonged, as was illustrated for example by Ang and Linn in 2014. The resulting sustained energy supply to the body from isomaltulose is reflected in the prolonged shape of the blood glucose concentration response curve.
Lower blood glucose and insulin response
The lower blood glucose and insulin concentrations after isomaltulose than after sucrose (or glucose) ingestion is evident for several population subgroups (see below). Consequently, isomaltulose has a low glycemic index (GI). Using standardized methodology, isomaltulose has a GI of 32 as reported the University of Sydney Glycaemic Index Research Service, which list isomaltulose in an online searchable database GI database. The GI value of 32 compared to 67 for sucrose, and 100 for glucose, makes isomaltulose a particularly low-GI carbohydrate (GI<55). Confirmation of a low glycaemic response to isomaltulose is provided in numerous studies for different population groups including healthy people, overweight or obese persons, prediabetic persons, and type 1 or type 2 diabetes patients (e.g.). Among these studies, all show the lower blood glucose response of isomaltulose and where tested also show the associated reduction in the blood insulin response. A significant role for the incretin hormone GLP-1 has been established, which occurs in response to distal carbohydrate absorption and limits the rise in blood glucose concentration after a meal. A claim corresponding to the low glycemic response of isomaltulose and its potential to lower the blood glucose response to foods when replacing other sugars has been approved as laid down in EU legislation following the publication of a positive opinion from the European Food Safety Authority.
Improvements to blood glucose control
In the long-term when eating a diet including carbohydrate, reducing undesirably high concentrations of glucose in blood, and the associated demand for insulin, is supportive of the prevention and management of diabetes mellitus, cardiovascular disease, and possibly overweight and obesity--as indicated by the International Carbohydrate Quality Consortium consensus of expert nutrition scientists. Continuous monitoring of 24-h blood glucose concentration following diets including isomaltulose instead of sucrose lowers the blood glucose profile over the day, as a result of a lower blood glucose response to individual meals. A lower glycemic diet can be achieved by choosing foods with low or reduced glycemic properties instead of many commonly consumed foods. More specifically by choosing lower GI foods from within each food group (fruit, vegetable, whole gains, etc). Isomaltulose in place of sucrose and many other carbohydrates has enabled the glycemic profile of foods to be reduced. Several studies provide evidence of improvements in both blood glucose control and lipid metabolism in both diabetic and non-diabetic persons upon regular consumption of isomaltulose when compared with other carbohydrates such as sucrose, maltodextrin, or glucose.
Effect on fat oxidation
When compared with other ingested carbohydrates, isomaltulose ingestion associates with higher rates of fat oxidation and lower rates of fat storage. Mechanistically this involves a lower blood glucose concentration, which then provides a lower stimulus to insulin secretion, which in turn allows more fatty acids to be released from adipose tissue for oxidation as an energy source. The lower insulin concentration also decreases carbohydrate oxidation so allowing more fatty acids to be oxidized. A lower insulin concentration also lowers the rate of liver free-fatty acid recycling via plasma triglycerides and reduces the storage of triglycerides in adipose tissue. Practical implications seem to be several, higher rates of fat oxidation occur after isomaltulose than after higher glycaemic carbohydrates ingestion in many studies, yet the studies have different foci:
- Isomaltulose in weight management and body composition
Studies have looked at the effects on fat oxidation and other metabolic responses when replacing sugars with isomaltulose in meals (or drinks) taken by healthy or overweight to obese adults, with or without impaired glucose tolerance, and while largely sedentary. These studies have shown isomaltulose to have a role in reducing body fatness, at least central obesity. Abdominal fat decreases when consuming isomaltulose instead of sucrose (sugar replacement) or instead of breakfast calories (largely carbohydrate replacement).
- Isomaltulose in physical activity and sports nutrition
Others studies have looked at the potential benefits of slow and sustained release of carbohydrate during physical activitity. Using isomaltulose in place of other ingested carbohydrates, higher rates of fat oxidation also occur during endurance activities, when preserving glycogen is important. In addition, trials using a recovery protein drink have shown that incorporating isomaltulose and a nutritional supplement (?-hydroxy- ?-methylbutyrate ) may help recovery from resistance exercise--so reducing of muscle damage and improving athletic performance.
- Isomaltulose in type 1 diabetes patients engaging in physical activity
In people having type 1 diabetes, the ingestion of isomaltulose instead of glucose during moderate carbohydrate loading prior to exercise improves blood glucose control, protects against hypoglycemia while maintaining running performance. The reduced risk of exercise-induced hypoglycemia arises in part from need of less insulin by injection (50% lower) when using isomaltulose and in part from the higher contribution of fat oxidation to energy metabolism, which preserves glycogen stores to counter the risk of hypoglycemia.
Cognitive performance (mood and memory)
Carbohydrates by way of the glucose they supply can improve cognitive performance (mood and memory). Several studies comparing isomaltulose with higher glycaemic carbohydrates taken at breakfast show improvements in mood and memory in healthy children, middle-aged adults, and aged adult.
Oral health
Isomaltulose is 'kind to teeth'. Fermentation of carbohydrates by bacteria in the mouth (especially on the teeth) is responsible for the formation of dental plaque and oral acids. The acid initiates tooth demineralisation and tooth decay (dental caries). Isomaltulose largely resists fermentation by oral bacteria and is the first carbohydrate of its kind to show by pH telemetry a negligible acid production on teeth. The evidence is strong and provides the basis for 'toothkind' claims approved by both the Food and Drug Administration in the USA and European authorities following a positive opinion from the European Food Safety Authority .
Maps Isomaltulose
Use
Isomaltulose is used in foods, drinks and health products owing to several of its properties:
Taste profile. Isomaltulose is used as a food ingredient and alternative to other sugars and maltodextrins in foods and beverages. In these it provides a natural sucrose-like sweetness profile with a sweetening power about half that of sucrose, and no aftertaste.
Moisture. Isomaltulose has very low moisture absorption (hygroscopy) therefore it has free-flowing properties in instant powders, which because of their low risk of lumping can easily be made up into drink or other type of product.
Stability. Isomaltulose is highly stable during processing, including acidic conditions and environments where bacteria might grow. In sports beverages, for instance, isotonicity (osmotic pressure equal to that of fluids in the body) can be maintained during storage over the beverage's shelf-life.
Applications. Examples of products in which isomaltulose finds application include: baked goods, pastry glazings and icings, breakfast cereals, cereal bars, dairy produce, sugar confectionery (e.g. chocolates, jellies, chewy confections and chewing or bubble gum), frozen desserts, fruit-juice beverages, malt beverages, sports beverages, energy drinks, instant drinks, and special and clinical nutrition feeds.
Recognition. The use of isomaltulose in foods and drinks is recognised in many regions worldwide. For example, it is generally recognized as safe (GRAS) by the U.S. Food and Drug Administration, is approved as a novel food by the European Commission, and in Japan has the status FOSHU (food for specific health use).
References
External links
- Marketing of isomaltulose as a novel food or novel food ingredient in the European Union
- Assessment of the glycaemic index of isomaltulose
- Oral health claims with isomaltulose in the USA
- Article on innovative low-glycaemic carbohydrates
- Webpages further describing Isomaltulose (Palatinose)
Source of article : Wikipedia
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