Sugar-Free Formulating

By Cindy Hazen, Contributing Editor

Few development projects are as simple as they appear on the surface. Take reformulating a product to meet a sugar-free claim. The least difficult step is the first: Remove the sugar from the formula.

Step two, choosing an appropriate sweetener to meet the products label requirements, might be easy enough, as might be calculating the percentage of high-intensity sweetener to use. Aspartame is 200 times as sweet as sucrose, for example, so the first formula pass might contain 0.10% aspartame to provide the sweetness of 20% sugar.

Now the formula totals 80.1%. Unless we add a bulking agent to bring the formula back to a 100% basis, every other ingredient will be amplified. The bulking agent we choose will impact solubility, mouthfeel, texture, browning or other functionalities. When we process and taste the finished product, well likely find aspartame has brought its own taste to the palate and that the other flavors have also changed because of the way they and other ingredients interact. And, the product might not look the way we envisioned. Its back to the bench for another round of reformulating.

A little knowledge can go a long way in reducing the number of times we tweak, recalculate and blend. Heres a short course.

High intensity, low levels

Acesulfame-K (also called acesulfame potassium), aspartame, neotame, saccharin and sucralose are chemically created sweeteners with high intensity. They do not contribute calories, in part because they are used in such small amounts, but also because of the way they are metabolized.

Sugar, or sucrose, is the benchmark by which sweetness is measured. Neotame is 8,000 times as sweet as sucrose. Sucralose is 600 times as sweet. Saccharin, acesulfame-K and aspartame are 200 times as sweet.

Yet, its not as simple as diluting an artificial sweetener to sugars standard because matching sweetness is not the same as matching flavor. These products carry their own unique characteristics. Sometimes the best results come from combining sweeteners, rather than allowing any one to dominate.

Sucralose is made from cane sugar by selectively replacing hydrogen atoms with chlorine atoms. This modification makes it unable to be digested or metabolized.

Manufacturers benefit from its process stability at high temperatures. There is zero loss during pasteurization at pH 2.8 at 93° C for 24 seconds, or during UHT at pH 6.5 at 141° C for 3.5 seconds. From a flavor perspective, depending on the application, sucralose can replace nutritive sweeteners up to 30% without altering taste.

Saccharin (C7H5NO3S) is the oldest artificial sweetener, dating back to 1879. From 1977 until 2000, FDA mandated a cancer-warning label. The warning was removed after the National Toxicology Program, Triangle Park, NC, delisted saccharin in the 9th edition of its  "Report on Carcinogens" in May 2000.

Aside from its checkered past, the sweeteners bitterness can be a disadvantage. However, it may have economic advantages if used in combination with another sweetener. In Alternative Sweeteners," (CRC Press, 2001), Lyn OBrien Nabors suggests that a 30% saccharin:70% aspartame blend does not impart bitterness, and reduces the cost of using aspartame alone. If used as the sole sweetener, a masking agent may be required. It is stable over a wide range of temperature and pH.

Neotame is a cousin to aspartame. Chemically, it is a dipeptide of phenylalanine and aspartic acid. In some products, such as beverages and chewing gum, it will extend sweetness. It will enhance fruit flavors. At nonsweetening levels it is used as a flavor modifier. Because it carries its own taste profile, it should not be used as a direct replacement for sugar, but it works well with other sweeteners. In a carbonated soft drink, 9% sugar equivalent may be replaced with 20% total sweetness from neotame, 75% sweetness from aspartame and 5% sweetness from acesulfame-K. This translates to the formula as 0.000225% neotame, 0.03375% aspartame, and 0.00225% acesulfame-K.

Aspartame is made up of phenylalanine, aspartic acid and a methyl ester. Aspartame has what many consider the cleanest sweetness profile of any of the alternative sweeteners, and the one that comes closest to the taste of sugar," says Ihab E. Bishay, Ph.D., senior director business development/application innovation, Ajinomoto Food Ingredients, Chicago.

Because aspartame does not introduce any off-flavors, it may be used as the sole sweetener in a variety of product formulations. Aspartame works well with a wide variety of flavor profiles, such as vanilla, chocolate, fruit flavors, citrus, minty flavors, etc.  In many cases it has even been shown to enhance some of these flavors without altering or unbalancing their profiles," Bishay says.

In combination with acesulfame-K it has an important synergy. Depending on the ratio, one can see synergies between 15% and 25%," Bishay says. However, besides this quantitative synergy, the product formulator needs to be aware of the overall taste profile of the blend, which is optimum somewhere around 80:20 to 70:30 ratios of aspartame: acesulfame-K."

Acesulfame-K is heat stable across a moderate pH range. It can be used in baking or in moderately acidic products like carbonated beverages. Its also used in chewing gum.

Aspartame works well in beverages, chewing gum, yogurt and many other applications. The effect of processing should be considered. In UHT processing, 0.5% to 1.5% is lost, and less than 1% is lost in HTST. Aspartame should not be used in products requiring retort processing or neutral/high-pH products that are not refrigerated," Bishay says.  Refrigerated products such as chocolate milk can be formulated with aspartame and still have the normal shelf life of their sugar-sweetened counterparts."

Ajinomoto is developing a new ingredient, advantame, that is a sweetener and flavor enhancer (currently approved FEMA GRAS as a flavor enhancer) that is 20,000 sweeter than sugar," says Bishay. It will be able to replace a portion of the sugar and calories in products while maintaining the same great taste, or enhancing the flavor of the beverage while reducing cost. The increased awareness of added sugar and calories together with the rising cost of sugar will ensure that the sugar-reduction trend will continue to gain momentum for some time to come."

Sugar alcohols

This class of sweeteners, also called polyols, is typically produced through hydrogenation of the base sugar. For example, xylose is hydrogenated to produce xylitol, and lactose is hydrogenated to produce lactitol," explains Eric Reamer, associate industry manager, beverage and confectionery, Danisco USA, Inc., New Century, KS.

The company also produces polydextrose, a synthetic carbohydrate polymer produced from dextrose. Although this product does not significantly contribute to sweetness, it is often used in sugar-free formulas to maintain calorie reduction while replacing some of the bulk lost when substituting a high-intensity sweetener for sucrose or HFCS."

Polydextrose contributes 1 kcal per gram. Dextrose or maltodextrin are alternative bulking agents. These will add 4 kcal per gram, just as sugar or sucrose do. They will also add mild sweetness. Dextrose, a glucose isomer, has approximately 0.7 times the sweetness of sugar. Dextrose equivalent (DE) is a term often used to convey relative sweetness of maltodextrins. Sweetness decreases with lower DE values.

Other options for reducing calories while bulking up are soluble fibers such as inulin and oligofructose, derived from chicory roots. Inulin has about 10% the sweetness of sucrose and contributes 1.5 kcal per gram. Oligofructose is the product of partial hydrolysis of inulin. It is 30% to 65% as sweet as sucrose. It is more soluble than sucrose and less stable in acidic conditions. Another advantage is that it reduces the artificial aftertaste of some high-intensity sweeteners.

Soluble corn fiber, also called digestion-resistant maltodextrin, is flavorless and soluble in water up to 70% w/w. It has 1.6 kcal per gram.

When calculating caloric contribution of polyols, one size does not fit all. The average is 1.6 kcal per gram; however, maltitol contributes 3 kcal per gram.

Xylitol is most often seen in mints, gums and other confections," says Reamer. It has a clean sweetness with a profile and intensity quite similar to sucrose. Due to its high negative heat of solution it works very well with mint type flavors. As it dissolves in your mouth, it produces a pronounced cooling sensation, which is very complementary to these flavors. Xylitol also works quite well with most citrus flavors."

Lactitol is often seen in bakery, dairy and sugar-free chocolate applications.  It also has a clean sweetness, but is significantly less intense than sucrose (only about 30% to 40% as sweet)," Reamer says.

Maltitol is seen in a wide variety of confectionery, dairy and bakery applications.  Maltitol is one of the most widely used polyols, as it works well in many diverse applications. It has a clean sweetness with approximately 80% of the sweetness intensity of sucrose," Reamer says.

Sorbitol is also used in bakery, dairy and confectionery items. It has 60% the sweetness of sucrose.

Mannitol is typically used in confectionery, primarily gum. It is about 50% as sweet as sucrose.  Both mannitol and sorbitol require a laxation claim in accordance with FDA regulations (Title 21 of the Code of Federal Regulations, Part 180, Section 25(e)).

Sugar alcohols allow calorie reduction and elimination of sugar from formulas. Xylitol has only around 60% of the caloric content of sucrose, and maltitol and lactitol are only at around 50%," says Reamer. Other pros include diabetic suitability and noncariogenic properties.  In fact, xylitol is known to be cariostatic and has studies supporting a variety of oral-health attributes. The primary con for reformulating with polyols would be price. Replacing sucrose or HFCS with polyols will add cost to the formula, although much of this may be offset by offering a premium product with reduced-sugar or -calorie claims. Some polyols (including lactitol) also have a reputation for poor digestive tolerance. However, this can typically be avoided if they are consumed in moderation."

Because polyols do not contain reducing groups, they are heat stable up to 177° C.

Naturally sugar-free

When the label requires both a natural and sugar-free, low- or reduced-calorie claim, there are a few ingredients the developer can turn to. Monk fruit, also called luo han guo, is native to Southeast Asia. The fruits sweetness is released by steeping the fruits pulp in hot water. The resulting spray-dried extract is around 200 times sweeter than sugar and is calorie-free. It received GRAS status in January 2010. This fruit-based sweetener is recommended for use in beverages, cereals, baked goods, confectionery and dairy products.

Stevia offers other plant-based sweetener ingredients derived from naturally occurring glycosides. Each of these glycosides has a different relative sweetness compared to sugar. One of the most abundant glycosides, rebaudioside A (reb A), is approximately 400 times sweeter than sugar.

Jason Hecker, vice president global marketing and innovation, PureCircle Limited, Oak Brook, IL, says, Stevia sweeteners work across a wide range of flavors, although some work better than others, such as peach, mango and other tropical fruits."

One of the companys stevia extracts is comprised of nine steviol glycosides, with reb A comprising more than half. This stevia extract works great with more complex flavors like chocolate, coffee and tomato," Hecker says. Adding a small amount of flavor, such as vanilla or sugar flavor, can complement the flavor profile of stevia. The overall sweetness profile may vary, depending on the combination of steviol glycosides in a sweetener. By balancing acid and flavor, a better profile can be developed."

For the blend or straight reb A, labeling is simply stevia leaf extract." But dropping in this label-friendly ingredient is not that simple. It is very important to balance the ingredients properly to create a successful product," Hecker cautions. It is not as easy as just switching out the artificial high-intensity sweetener with stevia. It takes some work to adjust the acids and other flavor notes to resemble the target product."

Stevia can enhance flavors already present in a product, or the ingredients in a formula can affect how we perceive the sweetness from stevia. A starch or fiber thickener may mask some of the taste notes, while xanthan gum has little effect on flavor," Hecker says. 

Stevia sweeteners are stable through typical food- and beverage-processing conditions. If the formula pH drops around 2.0, some steviol glycosides undergo hydrolysis and may impact the flavor notes," Hecker says.  

Stevia products are used in all product categories from beverages to baked goods. For sugar reductions over 50%, the lingering flavor notes may become more apparent and additional flavor modifiers incorporated," Hecker says.

And there lies the rub. If developers dont anticipate the way sweeteners are perceived and how they play with other ingredients under stressful conditions, they might not be out of the game, but its back to the bench.

Cindy Hazen, a 20-year veteran of the food industry, is a freelance writer based in Memphis, TN. She can be reached at [email protected].

Start With the Label

In regulatory seas, FDA offers clear navigation for steering a sugar content claim. In the absence of sugar (e.g., "sugar-free," "free of sugar," "zero sugar," "sugarless," etc.), product labels must also bear additional, conspicuous calorie statements or advise that the food is not a reduced calorie food," or not for weight control."  (Title 21 of the Code of Federal Regulations, Part 101, Section 60).

A food cannot be labeled sugar-free (or similarly) unless the food contains less than 0.5 grams of sugar per reference amount customarily consumed and per labeled serving. 

While it may seem obvious that a food that is labeled sugar-free shouldnt contain an ingredient that is a sugar, it can happen when using blends of ingredients such as seasonings or flavor bases. In these cases, the listing of the ingredient must be followed by an asterisk that refers to a statement below the list of ingredients that states something like adds a trivial amount of sugar."

Living up to a product claim or calorie disclaimer is important to avoid FDA scrutiny. Meeting goals set by marketing departments and the claims they envision is another conundrum.