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 product’s 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, we’ll 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. It’s 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. Here’s 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, it’s not as simple as diluting an artificial sweetener to sugar’s 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 sweetener’s 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 O’Brien 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. It’s also used in chewing gum.
