Isomalt is a unique, excellent tasting sugar-free bulk sweetener. Because the same amount of isomalt is used in products as would be used if they were sweetened with sugar, isomalt-containing products have the same appearance and texture as those made with sugar.
Discovered in the 1960s, isomalt is made from sucrose and looks much like table sugar. It is white, crystalline and odorless. Isomalt is a mixture of two disaccharide alcohols: gluco-mannitol and gluco-sorbitol.
Isomalt has been used in the United States for several years in products such as hard candies, toffees, chewing gum, chocolates, baked goods, nutritional supplements, cough drops and throat lozenges. It has been available in Europe, however, since the early 1980s and is currently used in a wide variety of products in more than 70 countries worldwide.
Isomalt offers benefits that suit changing life-styles and contemporary guidelines for healthy diets. It enlarges food choices for the growing number of people who would like to make moderate, but not extreme, improvements in their diet. It is ideal for consumers who want to adopt a healthier lifestyle, as long as foods still taste good.
Because of its lower caloric value and other health benefits, isomalt is useful for people who are trying to reduce their total energy intake moderately while still being able to enjoy their favorite desserts, candy, and other sweetened foods occasionally as part of meals or snacks.
The two-step process begins with sucrose. First, an enzyme rearranges the linkage between glucose and fructose in sucrose. In the second step, two hydrogens are added to an oxygen in the fructose portion of the disaccharide. Approximately half of the fructose portion of the original disaccharide is converted to mannitol and about half of the fructose portion of the original disaccharide is converted to sorbitol. Therefore, isomalt contains two different disaccharide alcohols: gluco-mannitol and gluco-sorbitol.
The molecular changes that occur in these steps make isomalt more stable – chemically and enzymatically – than sucrose. Isomalt’s stability is the reason for many of its health benefits and the large variety of products which it can improve.
Besides the characteristics that result from isomalt’s volume and texture, isomalt can be heated without losing its sweetness or being broken down. Therefore, it is predominantly used in products that are boiled, baked or subjected to higher temperatures.
Isomalt absorbs very little water. Therefore, products made with it tend not to become sticky. This means that candies, for example, can be put into a packet without each being wrapped separately, a convenient and appealing attribute for environmentally conscious consumers. Another advantage, resulting from this property is that, since the products do not absorb moisture, they have a longer shelf life.
Isomalt enhances flavor transfer in foods. It dissolves more slowly in the mouth so that candies with isomalt have a longer lasting taste. Isomalt does not have the often undesired “cooling” effect of some other polyols. Its sensory properties make isomalt an excellent ingredient for candies, chocolates, baked products and flavored applications such as fruit flavored candy, coffee and chocolate.
Isomalt’s sweetening power depends on its concentration, temperature and the form of the product in which it is used. When used alone, it contributes 45% to 65% of the sweetness that would result from the same amount of sucrose.
Isomalt is often used in combination with intense sweeteners. Isomalt gives products bulk, texture and mild sweetness, while the intense sweetener brings the level of sweetness up to what it would be if sugar were used. An additional advantage of such combined usage is that isomalt tends to mask the bitter aftertaste of some intense sweeteners. Synergistic effects in sweetening power occur when isomalt is combined with either intense sweeteners or other volume providing sweeteners.
Isomalt, like all polyols, is a low digestible carbohydrate which is only partially digested in the intestines. In the lower part of the intestinal tract, the non-absorbed portion is metabolized by colonic bacteria.
Isomalt’s physiological characteristics are a result of this process: Isomalt does not promote tooth decay, has a very low blood glucose effect (low glycemic response), has an effect like dietary fiber in the gut and has only half of the caloric value of sucrose.
Lower Caloric Value: For food labeling purposes in the United States, an energy value of only 2 calories per gram is used for isomalt. Isomalt’s lower caloric value is partly due to the fact that intestinal enzymes are not able to easily hydrolyze its more stable disaccharide bond. Less of it is digested and, therefore, less absorbed from the small intestine into the blood, and this happens slowly.
Supports Gut Health: Daily intake of 30 g isomalt was demonstrated to promote an increase of the “good” bacteria in the large intestine, the bifidobacteria, demonstrating the prebiotic effect of isomalt. The water-binding property of isomalt may influence the structure of the content of the gut, making it softer. If the consistency of the feces is too soft, it can be regulated by cutting down intake and allowing some time for adaptation. Like dietary fibers, isomalt is broken down by the gut bacteria to so called short chain fatty acids (SCFA) and gases. SCFA have the advantage of decreasing acidity in the large intestine and some SCFA are discussed as being beneficial for a healthy epithelium in the large intestine.
Less Dental Caries Risk: Isomalt is anti-cariogenic and does not promote dental caries, because oral bacteria cannot readily convert it into decay causing acids. Therefore, the acidic conditions that lead to tooth demineralization do not develop after consuming isomalt, as occurs after eating sugar and other fermentable carbohydrates. Furthermore, isomalt cannot be converted by oral bacteria into polyglucan, the substance from which dental plaque is synthesized.
Isomalt can help repair early dental caries lesions. Its sweet taste stimulates the production of saliva, thus reducing acidity and increasing calcium levels on the tooth surface. These changes facilitate remineralization of areas previously damaged by acidic conditions in the mouth due to fermentable carbohydrate consumption.
The Food and Drug Administration (FDA) allows manufacturers of sugar-free isomalt-containing products to make the health claim, “Does not promote dental caries,” if those products do not reduce plaque pH to less than 5.7 during or for up to 30 minutes after consumption.
Very low blood glucose and insulin response: Due to the metabolism described above, isomalt hardly influences blood glucose or insulin after intake as demonstrated in a number of studies, thus isomalt is very low glycemic. Isomalt is an ingredient, a useful tool within the total diet, that can contribute to providing low glycemic products to consumers interested in this health benefit. In particular those consumers are addressed that are interested in a healthy lifestyle (management and prevention of obesity, diabetes etc., being on a ‘low carb diet.’) There is a growing body of evidence that shows that a low glycemic diet can help in the management and prevention of obesity, diabetes and cardiovascular diseases.
A petition to affirm the GRAS (Generally Recognized as Safe) status of isomalt has been accepted for filing by the FDA. Isomalt has been used in the United States since 1990. It is marketed in the U.S. by Palatinit of America, Inc. and Beneo Group.
The World Health Organization’s Joint Expert Committee on Food Additives (JECFA) evaluated the safety of isomalt and concluded that there is no need for a numeric (limited) acceptable daily intake (ADI). JECFA established an ADI for isomalt of “not specified,” the safest category in which JECFA can place a food ingredient.