When bakers reformulate products to reduce or eliminate sugar, often with an accompanied reduction in calories, the revised formulations require ingredients that restore lost volume as well as sweetness. Because sugar also participates in the Maillard browning reaction and tenderizes baked foods through its action on both the gelatinization of starch and denaturation of protein, it is often, but not always, necessary to include ingredients with these functionalities.
No single ingredient replaces the functionality of sugar (sucrose) in all applications. Thus, formulators use a systems approach, which combines ingredients that provide solids, sweetness and more.
The Food and Drug Administration defines sugars as the sum of mono- and disaccharides. Therefore, other carbohydrates can be used to replace sugar, as long as they are not mono- or disaccharides. These ingredients are typically quantified on the Nutrition Facts panel as sugar alcohols (polyols) and fiber and are best recognized for their solids or bulking contribution to formulations.
What makes these carbohydrates different from sugars is their digestibility. Polyols are resistant to normal digestive enzymes and are more slowly absorbed. This results in a reduction of energy content, which is reported as calories, as well as a reduction in glycemic response in relation to other sweeteners. Fiber is completely resistant to digestion and therefore contributes no calories and has a zero glycemic response. Nonsugar, bulking carbohydrates used in no- and reduced-sugar baked foods should be neutral in color and without flavor or odor. Depending on the application, often one or a combination of high-intensity sweeteners is necessary. High-intensity sweeteners alone cannot do the job because very little is used to achieve a sweetness level similar to the sugar-sweetened product. They must be used in combination with some type of bulking agent for solids.
For example, Tate & Lyle, Decatur, IL, markets an ingredient solution for nosugar-added baked foods called Bakery Rebalance 706. This ingredient system, which includes Splenda brand sucralose in combination with Tate & Lyle soluble fibers and starches, is suitable for use in a wide variety of no-sugaradded and reduced-calorie baked foods including cakes, cookies, brownies, muffins, creme fillings, fruit fillings and icings. Using this solution system approach ensures that the sucralose, which is used at a very low level because it is about 600 times sweeter than sucrose, is uniformly incorporated throughout the baked food matrix.
Products made using this solution deliver added fiber, substantial calorie savings and a reduction in sugar levels to the consumer. Benefits for the manufacturer include simple optimizing of sweetness levels, easy dispersion of small quantities of high-intensity sweetener in dough and good moisture retention in storage. Usage level is about 10 to 12% of the overall formula. Other bulking agents might need to be added to the final formula to meet the no-sugar-added claim. Bakery Rebalance 706 is a mere 1.3 Cal per g, compared with sugar’s 4 Cal per g.
MALTITOL: A CLOSE MATCH
If eliminating sugar is the sole objective, there are a number of low-calorie sugar substitutes in the marketplace that also assist in providing bulk. Their use may result in a reduction in calories, depending on the application. For example, maltitol is a disaccharide polyol produced by the hydrogenation of the carbohydrate maltose. Being about 90% as sweet as sucrose with a similar taste and body, maltitol in its many forms has application in most baked foods.
"Maltitol behaves more like sugar than any other polyol," said Carl Jaundoo, Ph.D., associate program coordinator, Roquette America, Keokuk, IA. "Bakers can use it to replace sugar in most products with very minimal formulation or process change. It is also compatible with high-intensity sweeteners; however, in many baked food applications, high-intensity sweeteners are not required due to maltitol’s superior sweetness."
Very important for the baking industry, maltitol is thermally stable up to 200°C (392°F) and is not fermented by yeast. It also does not participate in the Maillard browning reaction, which can be good or bad, depending on the application. FDA allows the use of a caloric value of 2.1 Cal per g for maltitol powder, which is almost half the calorie content of sugar.
"Maltitol powders are formed by hydrolytic conversion of cornstarch to high-maltose syrup, followed by hydrogenation, purification and solidification to obtain dry, free-flowing powders," said Dr. Jaundoo.
Other forms of maltitol have application in baked foods. For example, maltitol syrup is a specialty hydrogenated starch hydrolysate with a minimum of 50% maltitol on a dry basis. "The syrup form imparts specific characteristics such as humectancy and viscosity to applications," said Dr. Jaundoo. There are similar syrups that contain less than 50% maltitol. These are simply referred to as polyglycitols (hydrogenated starch hydrolysates, or HSH).
"All polyglycitols are mixtures of polymers of varying molecular weight. Usually they are liquids, at about 70 to 85% solids," said Peter Jamieson, manager of applications research, SPI Polyols, Inc., New Castle, DE. "Sweetness depends on the maltitol level in the syrup and may range from 30 to about 80% the sweetness of sucrose."
Maltitol syrups and polyglycitols are stable, water-soluble, sugarless syrups that are generally non-crystallizing. "Maltitol syrups are especially suited for no-sugar-added fruit-based fillings," said Dr. Jaundoo. "They typically provide sufficient sweetness to allow formulation without the need for highintensity sweeteners.
"Maltitol syrups can also be used in baked foods, but the total water content of the recipe must be adjusted to achieve similar results to those produced using dry ingredients," he continued. Maltitol syrups provide 3 Cal per g.
Both maltitol powders and syrups are available in a variety of solids and sweetness levels. The powders also come in a variety of particle sizes to complement specific applications.
For example, both Roquette and SPI Polyols have several particle sizes to cover a variety of baked foods. This includes all types of biscuits such as wafers, filled or unfilled, chocolate-based, sandwiches, shortbread-type biscuits; pastries including muffins, brownies and cheesecakes; and select breads. "Maltisorb P35 SK has a very fine particle size (40 microns), making it ideal for creme fillings and icings," said Dr. Jaundoo. "About 3% starch is added as a flow aid. And it’s 96.5% maltitol, on a dry basis, so it functions quite similarly to powdered sugar in these applications.
"There’s also Maltitol 300 FD, which was developed specifically for baked foods," he continued. "It has a standard mean particle (250 microns) and has a crystalline structure designed to resemble the dissolution characteristics of sugar in bakery applications." At about 90% maltitol on a dry basis, this polyol works very well in baked foods that start out as a batter.
SPI Polyols markets Maltisweet MH80 maltitol syrup, which contains greater than 70% maltitol on a dry basis and is balanced with longer chain polyols. "This mixture provides baked foods with exceptional sweetness and functionality in a 75% solids syrup," said Mr. Jamieson. "The high sweetness level of the ingredient enables bakers to reduce or eliminate the use of expensive high-intensity sweeteners, lowering overall product cost and reducing handling within the plant." Common applications include cakes, cookies, fillings and nutrition bars.
Beside maltitol and maltitol syrups, the two other most common polyol ingredients used to bulk and sweeten baked foods are polyglycitol syrups and sorbitol. "Like maltitol ingredients, sorbitol can be used on a weight-by-weight basis as a replacement for sucrose in baked foods. It is 60% as sweet as sucrose, so if additional sweetness is desired, highintensity sweeteners can be included in the recipe," said Mr. Jamieson. "In addition, sorbitol is an excellent humectant, freeze-point depressant, crystallization inhibitor, plasticizer and cryoprotectant for icings and fillings.
"Polyglycitol syrups are a specialty category of hydrogenated starch hydrolysates. These syrups are based on sorbitol and maltitol, both of which are present in levels less than 50%," he continued. "They contain lesser amounts of hydrogenated oligo- and polysaccharides and maltotriitol. Syrup is its typical form, but it can also be dried and supplied as a solid product."
For example, SPI’s Stabilite SD polyglycitol powder comes in two varieties: SD-30 and SD-60. Both are low-sweetness, long-chain polymer powders that are higher in molecular weight and lower in hygroscopicity than typical polyglycitol products. These attributes provide more controlled viscosity during processing. SD-30 can be dissolved in water to produce a clear, noncrystallizing syrup at a concentration up to 75%, while SD-60 can do the same at a concentration up to 55%. The molecular weight of SD-30 is approximately twice that of typical polyglycitol solutions, and the molecular weight of SD-60 is approximately twice that of SD-30. This offers a wide range of viscosities in solution.
"These polyglycitol powders are nonreactive and have been used as a cryoprotectant and carrier during processing of sensitive ingredients," said Mr. Jamison. For example SD-30 has been shown to extend the viability of yeast during the freeze-drying process, while SD-60 has been used to carry enzymes such as xylanase, which are used in bread making.
Traditional maltitol powders and syrups, as well as polyglycitol syrups, do not contain fiber. However, it is possible to produce a variant of polyglycitol that contains enough fiber to contribute to the fiber content of the baked food. "Polysorb FM, with varying amounts of fiber, starts with dextrin, rather than cornstarch," said Dr. Jaundoo. "It provides all the functionality and benefits of the other maltitol ingredients with a further reduction in glycemic index and the healthful benefits of soluble fiber." Maltitol syrups with fiber range in calorie content from 2.4 to 3 Cal per g.
WHEN FIBER COUNTS
When boosting the fiber content of a baked food is also a part of a reducedsugar formulation objective, many bakers turn to polydextrose, a randomly cross-linked condensation polymer of dextrose, sorbitol and citric acid. This bulking agent is not sweet; however, when used in conjunction with one or a blend of high-intensity sweeteners, it can partially replace the sugar in bakery products. Though a carbohydrate, polydextrose is not digested like regular carbohydrates because it is a soluble fiber that is only partially metabolized by the body. As a result, polydextrose contributes only 25% of the calories of fully digestible carbohydrates such as sugar (1 Cal per g compared with 4 Cal).
In addition, polydextrose elicits a low-glycemic response, which makes it suitable for products formulated for diabetics. "Polydextrose can be instrumental in the development of bread and sweet baked foods that are reduced in sugar, lower in calories, low glycemic and also high in fiber," said Donna Brooks, regional director, Danisco, Elmsford, NY.
"As a low-calorie specialty carbohydrate/bulking agent, polydextrose can improve the flavor, texture and mouthfeel of sugar-free and reduced-sugar bakery products," she continued. "Polydextrose possesses many of the functional benefits of sugar without being sweet. Because it is compatible with sugars and high-intensity sweeteners, polydextrose allows the sweetness of formulations to be easily balanced. The clean, neutral taste of polydextrose also helps mask off-notes that sometimes result when ingredients such as soy proteins, vitamins, minerals and others are added to fortified bakery products."
Danisco’s Litesse polydextrose range provides a variety of ingredient forms to meet many application needs. "Litesse is unique in its ability to vary from a bland, neutral powder through to a colorless, mildly sweet liquid," said Ms. Brooks.
"Polydextrose has a similar functionality to sucrose in baked foods. For example, it alters thermal setting properties by delaying gelatinization of starch, and most of the Litesse polydextrose ingredients undergo Maillard browning — just like sugar," she continued. "It also provides humectancy to improve texture and mouthfeel and extend shelf life.
In multicomponent bakery products such as pies or filled pastries, polydextrose serves to inhibit moisture migration. And in low-moisture applications, polydextrose acts as a crisping agent.
NOT SO SWEET, PLEASE
Alternatively to making the removal or reduction of sugar a content-claim goal, sometimes a formulation objective is to simply make a sweet baked food not so sweet. Domino Foods, Inc., Baltimore, MD, offers an ingredient solution to assist in taking some of the sweet out of sweet.
Envision Flavor and Texture Modifier is produced using the company’s patented co-crystallization technology. It is about 97% sucrose and 3% maltodextrin, which is a minimally sweet bulking carbohydrate. This unique ingredient allows a baker to control the sweetness of a product. It works very well in baked food fillings where the functional properties of sucrose are needed for texture, structure and dispersion without all the sweetness, according to the company. The physical structure of this flavor modifier is microsized crystals bound together in a sponge-like structure.Sweet is a taste we are born to love. Helping consumers to control caloric intake from sweets is a science.