Tagatose is a low carbohydrate functional sweetener, very similar to fructose in structure. It is naturally occurring and can be found in some dairy products. Tagatose has a physical bulk similar to sucrose or table sugar and is almost as sweet. However, it is metabolized differently, has a minimal effect on blood glucose and insulin levels and furthermore provides a prebiotic effect. Tagatose is especially suitable as a flavor enhancer or as a low carbohydrate sweetener.
The U.S. Food and Drug Administration (FDA) has accepted the “Generally Recognized as Safe” (GRAS) notification for tagatose. It was launched in the U.S. market in May 2003, and is also used as a general-purpose sweetener in Korea, Australia and New Zealand. Tagatose is manufactured and marketed worldwide by SweetGredients GmbH & Co., and is sold in the U.S. through Arla Foods Ingredients amba. It can be used in ready-to-eat cereals, diet soft drinks, health bars, frozen yogurt/nonfat ice cream, soft confectionary, hard confectionary, frosting and chewing gum.
D-Tagatose is made via a patented procedure from lactose in a two-step process. In the first step, lactose is hydrolyzed to glucose and galactose. In the second step, galactose is isomerized to D-tagatose by adding calcium hydroxide. D-tagatose is then further purified by means of demineralization and chromatography. The final product is a white crystalline substance that is greater than 99 percent pure.
Because of its great taste, low carbohydrate impact and high functionality, tagatose can improve the quality of a wide range of foods when used either for its healthy effects at high doses or as a flavor enhancer at low doses. Tagatose creates unique opportunities to develop the healthy foods market by improving taste and enabling strong claims.
Tagatose can be used as a flavor enhancer. It creates a synergistic flavor-enhancing effect in combination with high intensity sweeteners and is therefore ideal for diet soft drinks giving a regular taste. Numerous application tests have demonstrated that tagatose greatly improves the flavor profile and mouthfeel of diet soft drinks when combined with aspartame, acesulfame-K and sucralose. Additionally, this combination also speeds up sweetness onset and reduces bitterness.
Furthermore, tagatose enhances specific flavors in various applications, such as mint and lemon flavor in sugar free chewing gum and mints. It also boosts creaminess and toffee flavor. These flavor enhancing benefits can be further exploited in a number of other products, including diet yogurts and tabletop formulations.
The physical properties of tagatose ensure ease of use in a wide range of functional foods, drinks and other applications. With the sweetness of sucrose, it can substitute sugar or polyols without significantly changing the processing parameters.
Tagatose is pH stable in acidic applications and can thus be used in products such as carbonated beverages as well as yogurts. And because of its easy crystallization properties, tagatose is ideal for use in frostings.
Due to its bulk and sweetness, tagatose can be used in small amounts in baking and products subjected to high temperatures to increase the moistness and flavor, while maintaining sweetness. However, the processing and preparing of foods containing tagatose must accommodate certain temperature reactivity, as tagatose containing products “brown” and caramelize more readily than sucrose containing baked goods.
The steps in the metabolism of tagatose are identical to those for fructose or fruit sugar but tagatose is incompletely absorbed. Only 15-20 percent of tagatose is absorbed in the small intestine. The major part of ingested tagatose is fermented in the colon by indigenous microflora, resulting in the production of short-chain fatty acids. The short chain fatty acids are absorbed almost completely and metabolized.
Extensive human testing has been conducted on tagatose to ensure its safety and human tolerance. With certain sensitive individuals, mild gastrointestinal discomfort (e.g., flatulence and laxation) may occur as with other low digestible carbohydrates.
Very low blood glucose and insulin response: Because tagatose is incompletely absorbed, it has a minimal impact on blood glucose (low glycemic effect) and insulin levels. The low glycemic effect of tagatose is confirmed in several clinical studies. A clinical study with an oral intake of 75 g of tagatose showed no increase in plasma glucose or serum insulin in either normal persons or people with Type II diabetes. Thus, tagatose is a useful tool for those interested in a low glycemic health benefit, particularly consumers endeavoring to manage or prevent obesity, diabetes, etc.
Prebiotic effect: Clinical research has shown that tagatose acts as a prebiotic, demonstrated by the increase of “good” bacteria in the large intestine and colon after consumption. Tagatose selectively promotes the production of butyrate and lactic acid bacteria, which are essential to maintaining a healthy digestive system. Like dietary fibers, tagatose is broken down by the gut bacteria to short chain fatty acids (SCFA). SCFA have the advantage of decreasing acidity in the large intestine and some SCFA are recognized as beneficial for a healthy epithelium in the large intestine. The unique combination of sweetness with the prebiotic effect enables creation of great tasting healthy products
Lower Caloric Value: For food labeling purposes in the U.S., an energy value of only 1.5 calories per gram may be used for tagatose. When using less than 3.33 g per serving of tagatose, foods and beverages in the U.S. are allowed to carry a “zero calorie” claim. When the amount does not exceed 0.5 g per serving of tagatose, foods and beverages in the U.S. are allowed to carry a “sugar free” claim.
Does Not Promote Tooth Decay: Tagatose does not promote dental caries. The conditions that normally lead to tooth decay after eating sugar and other fermentable carbohydrates do not occur after consuming tagatose. The Food and Drug Administration (FDA) has approved the use of a dental health claim for products containing tagatose as long as the retail product complies with all the requirements for a tooth-friendly product. The approved dental health claim may state, “Tagatose sugar does not promote tooth decay” or “Tagatose sugar may reduce the risk of tooth decay.” However, tagatose-containing products may not be labeled sugar free unless they contain less than 0.5 g per serving sugar.
Under the U.S. Food and Drug Administration’s (FDA) “GRAS notification system,” the manufacturer of tagatose made a self-determined Generally Recognized As Safe (GRAS) declaration for the sweetener and notified the FDA. After evaluating the GRAS notification submitted for tagatose, the FDA has accepted the GRAS notification. Tagatose may now be used in the U.S. food supply.
The World Health Organization’s Joint Expert Committee on Food Additives (JECFA) evaluated the safety of tagatose in June 2004 stating there is no need for a limited acceptable daily intake (ADI) of tagatose. JECFA has, therefore, established an ADI of “not specified,” the safest category in which JECFA can place a food ingredient.
Tagatose was approved for use in foods and beverages by the Korean FDA in 2003, and was approved for use in foods and beverages in Australia and New Zealand in April 2004. Other regulatory approvals are under way in major markets worldwide.
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U.S. Food and Drug Administration, “Health Claims: Dietary Noncariogenic Carbohydrate Sweeteners and Dental Caries” in: Code of Federal Regulations, U.S. Government Printing Office, 2003, Sec. 101.80.