A new generation of sweeteners

Tagatose is found naturally in a number of foods: cheeses, milk and other common products.Tagatose is a monosaccharide in structure. The galactose molecule present in lactose is converted to tagatose using alkaline conditions, then concentrated and crystallized in a process much like the production of fructose from sucrose. Because of the position of chiral carbons, which makes the product technically a C-4 epimer of D-fructose, only about 20 percent of the sugar is metabolized. This provides a caloric value of about 1.5 calories per gram (sugar is about 4.0 calories per gram).

Crystalline tagatose is nearly as sweet as table sugar (92 percent as sweet as sucrose when presented in a 10 percent solution) but with a faster flavor onset, more like fructose. It is about 62 percent soluble in water at room temperature. Only about 25 percent of the product is absorbed, and the remaining 75 percent can produce the same laxation effects of other nonabsorbed products if used in high concentrations.

Spherix has licensed the product to Arla Foods of Denmark for sales in the food industry. Spherix retained the marketing rights for nonfood applications and has introduced its Naturex brand of tagatose for toothpaste, mouthwash and pharmaceuticals.

The product for the food industry is made in Hannover, Germany, by a joint venture between Arla and Nordzucker, Germany's second largest sugar producer. Arla Foods USA, Basking Ridge, N.J., supports American food processors in formulations using tagatose, under the brand name Gaio.

 It's recommended for use in cereals, desserts and other products that can use the functional characteristics to advantage. In addition to its low rate of metabolism, tagatose has a low glass transition temperature, low caramelization temperature and high melting point (134 degrees; C). Unlike glucose, it is not hydroscopic at 75 percent relative humidity and 30 degrees; C. It is stable at a fairly wide range of pH. Research in Denmark found it particularly effective as a glaze for cereal flakes and nuggets, replacing large amounts of sugar for the ready-to-eat cereal segment.

One of tagatose's most successful uses in the U.S. is in low-calorie frozen carbonated beverages -- it's a key ingredient in 7-Eleven's Diet Pepsi Slurpee. Tagatose and erythtitol provide the bulk and freezing point suppression needed to soft-freeze the carbonated beverage. Sweetness is added by a combination of sucralose and acesulfame K. Tagatose is credited with improving the overall flavor profile of the complex combination.

Because of its reduced level of carbohydrate metabolism, the sweetener can be used in products for low or no-carb diets. It is a good supporting ingredient for high-intensity sweeteners, improving the flavor profile and eliminating any chemical flavors. Because of the reducing power of tagatose, it is best used in foods that are low in protein, processed at low temperatures or use the low caramelization temperatures to advantage --in confections such as chocolate, caramels, ice cream, cereal, and meal replacements.

 One such product is produced by Pasco Beverages, Plant City, Fla. Available in five varieties, Light & Tasty Juices claim fewer calories and fewer carbs than their conventional counterparts. The apple juice, fruit punch, and lemonade varieties have 10 carbohydrates per serving (70 percent fewer carbs than comparable products), and the orange juice and orange juice with calcium have 45 percent fewer carbs and calories.