If, by a quirk of development, humans had developed a profound distaste for sweet flavors, food scientists would be scrambling to find ways to eliminate that taste while retaining the structure of the ingredients we call sweeteners. The wide-ranging function of these small carbohydrate molecules is too helpful to do without.
There is a place for both high impact (sweeter than sucrose) and low impact (less sweet than sucrose) sweeteners, and not just as flavorings. They also serve as humectants, browning agents, texturizers, osmotic actives and other tools.
A number of low-impact sweeteners offer these utilities without a lot of sweetness, and they are finding uses in the increasingly health-aware, safety-conscious marketplace. High- or low-impact technically defines a sweetener that affects insulin reaction -- and this is not just important to diabetics, this also impacts blood pressure and blood vessel plaque. High-or-low intensity refers to apparent sweetness.
Most of the newly introduced products that use these ingredients are beverages. That's because beverages are ideal carriers and the category is a growing one right now, although these sweeteners do have other applications.
Tagatose and trehalose are two of these up-and-coming low-impact sweeteners. Both technically have been around for several years, but were introduced as cost-effective products with self-affirmed generally recognized as safe (GRAS) status fairly recently. Both are produced from carbohydrates: tagatose from lactose (the sugar found in milk) and trehalose by enzymatic action on starch.
Generally, the sweetener market is in the hands of major companies. Capacities are large and startup costs are high. It usually takes a considerable time for a switch in sweetener use by major products, as was the case of the movement from sugar or invert sugar to high-fructose corn syrup.
These sweetener functions are frequently measured by dextrose equivalent (DE), which measures the amount of reducing power of the sweetener, roughly by the number of reducing ends of the saccharide fragments. Higher DE sweeteners are sweeter, thinner, and brown more easily and quickly.
Maltodextrins, available to very low DE, are not particularly sweet and provide more viscosity. But all of these sweeteners supply about 4 calories per gram, and are completely metabolized in the lower intestine.
Sucrose isn't measured by DE, is sweeter than the corn or other grain derivatives, provides body, and is totally metabolized. High-intensity sweeteners are very sweet, and generally have the functional characteristics of their carriers (maltodextrin, dextrose, lactose, etc.)
Change is slow, but eating into the mainstream market is a growing special needs market, populated by obese, overweight and diabetic consumers. Whether these people are watching calories, carbohydrates or the glycemic index, traditional sweeteners are not the answer. Indeed, some observers think this special needs market could become the mainstream market.
Regardless, the science behind these special sweeteners must be better understood by all food formulators.
Tagatose is made by hydrolyzing lactose with a special enzyme so the two monomers, galactose and glucose, can be separated by chromatographic columns. Tagatose was self-affirmed as GRAS in May 2001, by its developer, Spherix, of Beltsville, Md. www.spherix.com with a no-objection letter from FDA following in October.
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
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
One of tagatose's most successful uses in the
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.
Pacific Health Laboratories chose trehalose for a sports beverage called Accelerade because the sweetener has low insulin response and is slowly metabolized to provide long-term energy.
One such product is produced by Pasco Beverages,
The current front label trumpets Sucralose, but the next generation of packaging will also carry the Gaio name for tagatose. "Splenda is a good sweetener and it's neutral -- it has no negatives associated with it, like some other sweeteners. But consumers do recognize the name," says Rich McClelland, director of marketing for
"I get some calls from people who know about tagatose and its health benefits, but there hasn't been a lot of discussion in the popular press," he continues. "When people learn about it, you see the possibilities. We introduced the Light and Tasty line last January, so it's too soon to track its progress in the market."
Trehalose has been produced and consumed in increasing amounts in
The ingredient is produced by Hayashibara's patented enzyme process from corn starch and is marketed in North and
Trehalose has been used for decades in pharmaceutical and specialty applications at relatively high ingredient cost. Hayashibara's breakthrough manufacturing process from cornstarch, using two special enzymes, has enabled trehalose to be economical for the global food industry in a wide range of applications.
While the current label trumpets Splenda sucralose, there also is Tagatose in Pasco's Light & Tasty juices. The next generation of packaging will also carry the Giao brand name as Tagatose and it's health benefits will be recognized.
Trehalose is two glucose molecules linked together (in an alpha-alpha 1-1 linkage) in such a way that they do not expose reducing ends. That structure is novel: The lack of reducing ends makes it a non-reducing sugar. This means it can be used to stabilize amino acids without triggering a Maillard reaction, even in acidic foods.
It is a disaccharide, completely metabolized to glucose molecules and is absorbed in the small intestine. However, unlike glucose, it elicits a low insulin response and is metabolized slowly, providing energy over a sustained period and stabilizing blood sugar over a long period of time. While the insulin response is low, the glucose response is normal.
Trehalose is about 45 percent as sweet as sucrose, but with an extremely clean, mild flavor profile. It has a high glass transition temperature, and protects proteins during freeze-thaw cycles. This property is integral to its function in various food systems, including processed meat, poultry, frozen fish and surimi.
Trehalose has been introduced in a sports beverage called Accelerade by Pacific Health Laboratories,
Feeling your oats
A third sweetener, quite new, is described as a functional syrup made from oats or waxy barley, grains that contain a significant amount of beta glucan. The sweetener, Oatscreme, is manufactured by American Oats,
Oatscreme is made from grain, using a combination of enzymes to convert a slurry to the level of sweetness needed. Most of the sweetness comes from glucose, but the other saccharides are larger, which provides more viscosity and texture to frozen desserts.
The flavor of the syrup is exceptionally bland, and "it tastes a lot better than it ought to" given the components, says inventor Paul Whalen. "It has a nice, balanced flavor and great mouthfeel."
The syrup, made just before it is used in Oatscreme frozen dessert, contains about 33 percent solids, a little more than 2 percent protein, about 1.1 percent fat, and about a gram of dietary fiber per 85-gram serving. Caloric content of Oatscreme is about 130 calories per 85 grams. Oatscreme contains no added fat, sugar, or other ingredients except for flavors. The syrup is simply aerated and frozen.
Currently, the oat-based syrup would have to be refrigerated during shipment if it were to be used as an ingredient by other companies.
High-impact sweeteners currently on the market are used to advantage with some of these low-impact, functional sweeteners. In fact, in some cases, the combination of high- and low-impact sweeteners is the key to product success.
There are sweeteners on the drawing board and new ones coming on the market all the time , as well as new food products that are crying out for sweeteners with certain functionalities. It's a sweet science, but not entirely about being sweet.