As the public health crisis burgeons with more than 20 million diabetics and 60 million obese adults in the United States, strategies to reduce calories, specifically “sweet” calories, is a hot topic. Dairy foods formulators are responding by developing products that use low- or no-calorie sweeteners, which are alternatives to sugar and sugar’s closely related four-calories-per-gram carbohydrate-based sweeteners.
The most common approach is by partial or complete replacement of sugar or other carbohydrate sweetener with a combination of high-intensity sweeteners, polyols and other lower-calorie sweetening agents, including ingredients described as enhancers, herbs and plant extracts.
What do consumers know about these ingredients?The American Dietetic Association, Chicago, has been conducting nationwide surveys of consumer nutrition trends since 1991. The most recent survey - Nutrition and You: Trends 2008 - was conducted by Mintel International between Feb. 15 and March 7, 2008. The survey included telephone interviews lasting about 18 minutes with 783 respondents representing a nationally representative sample of the total over-18 U.S. population.
The aims of each survey have been to measure people’s attitudes, knowledge, beliefs and behaviors regarding food and nutrition, and to identify trends and understand how consumers’ attitudes and behaviors have evolved over time.
“In 2008, as in previous years, the American Dietetic Association’s public opinion survey takes a close look at trends in the U.S.,” says registered dietitian and ADA President Martin Yadrick. “For the public, the media and researchers alike, ADA’s survey provides a clear picture of consumers’ current attitudes, valuable insights into people’s perceptions of registered dietitians and an outstanding opportunity to trace the evolution of knowledge and beliefs about food and nutrition over the past 17 years.”
Respondents were queried about their knowledge of health-related foods and nutrients. Respondents were asked to use a scale of one (little knowledge) to five (greatest knowledge) to indicate how much they had heard about possible health-related effects of various foods or nutrients (see chart).
More than three in four people (78%) have heard a lot about low-fat foods and 72% have heard a lot about foods containing trans fat. Meanwhile, 3.5% said they had heard little or nothing about low-fat foods and 7.5% said the same about foods with trans fat. Allergen-free foods and probiotics command much less of the public’s attention. Less than 20% of respondents said they had heard a lot about these two items.
Foods and nutrients of which people were most likely to increase consumption in the past five years included low-fat foods (48%), omega-3 fatty acids (38%), garlic (36%), low-sugar foods (34%) and low-sodium foods (32%).
By a wide margin, foods containing trans fat were most likely to see their consumption reduced in the past five years, with 56% of respondents saying they had cut back on these foods. Low-sugar foods (20%), alternative sweeteners (18%) and low-carbohydrate products (17%) were the next most-often named.
At least half of all respondents said they had not changed their consumption of the following foods and nutrients: allergen-free foods (81%), probiotics (76%), soy-based products (63%), garlic (58%), low-carb foods (56%), berries (54%), omega-3 fatty acids (53%) and low-sodium foods and alternative sweeteners (52% each).
More details can be found in a PowerPoint presentation posted to www.eatrght.org/trends2008.
Alternative sweetener optionsThere are a number of alternative sweeteners available to dairy food manufacturers, some are considered natural and a few are even available certified organic.
Many developers are turning to fructose to replace some - never all - of the sugar in a formulation. Fructose is the sweetest of all naturally occurring carbohydrates - 1.7 times sweeter than sugar. It has been shown to exhibit a sweetness synergy effect when used in combination with other sweeteners with the relative sweetness of the blended sweeteners perceived as being greater than the sweetness calculated from individual components.
Relative sweetness of fructose in any dairy foods application depends on various processing and formulation conditions, including temperature, solids, pH and the presence of other ingredients. Fructose also contributes solids, which often are required when caloric-carbohydrate sweeteners such as sugar are replaced solely by high-intensity sweeteners. Depending on the application, the solids that come from fructose can reduce the solids required from other sources.
There are numerous other natural sugar alternatives being embraced by formulators. Some provide bulk in addition to reduced-calorie sweetness. Usage varies by application, with many working best in synergy with other sweeteners.
For example, tagatose has a physical bulk similar to sugar and is 92% as sweet without any aftertaste. In addition, it has been shown to have a synergistic flavor-enhancing effect in combination with other sweeteners. It only contributes 1.5 calories per gram, since only 15% to 20% of tagatose is absorbed in the small intestine. The major part of ingested tagatose is fermented in the colon by indigenous microflora, thus, it provides a prebiotic effect.
Tagatose is made via a patented procedure from lactose (milk sugar) in a two-step process. In the first step, lactose is hydrolyzed to glucose and galactose. In the second step, galactose is isomerized to D-tagatose by adding calcium hydroxide. D-tagatose is then further purified by means of demineralization and chromatography. The final product is a white crystalline substance that is greater than 99% pure.
The natural sweetener isolmaltulose is found in honey and sugar cane molasses as a disaccharide consisting of glucose and fructose. Commercially it is typically produced from beet sugar that has undergone a natural enzymatic rearrangement of the glucose-fructose bond. It is about half as sweet as sucrose while exhibiting the same balanced and natural taste profile, yet is non-cariogenic. Further, it is not lower-calorie, as it delivers four calories per gram just like sugar, but it does provide a host of functional benefits that many dairy processors are looking to offer in their products.
For example, isomaltulose is best known as being a low-glycemic carbohydrate that provides sustained energy in the form of glucose. It does this by being hydrolyzed and absorbed four to five times more slowly than sucrose, thanks to the strong binding of its glucose and fructose component. Thus, it has little effect on blood glucose levels, which has been shown to help avoid sugar rushes followed by hunger pangs. Isolmaltulose has also been shown to promote fat oxidation by increasing the use of body fat and fatty acids as energy sources.
Isomaltulose is resistant to microbial fermentation, making it attractive for use in dairy beverages. About a year ago, Japan’s Yakult introduced Bifia, a low-calorie, high-fiber fermented dairy shot-style beverage containing isomaltulose. Each 100-milliliter shot contains only 40 calories. A similar product was launched by Germany’s Dr. Oetker. New Dr. Oetker Vitalis Yofibra Probiotic Dairy Drink comes in portion-controlled 135-gram bottles, with each serving delivering 8.4 grams of fiber.
Polyols are also very helpful in lowering calories. Sometimes referred to as sugar alcohols because of their molecular configuration - part sugar and part alcohol - these nutritive alternative sweeteners are incompletely absorbed and metabolized by the body and consequently contribute fewer calories than sugars. However, not all are considered natural.
The natural polyol most often used in dairy foods is erythritol, which is about 70% as sweet as sugar and contains only 0.2 calories per gram. Erythritol is rapidly absorbed in the small intestine and eliminated by the body within 24 hours; thus, the laxative side effects sometimes associated with excessive polyol consumption are unlikely when consuming erythritol-containing foods. Because of its reduced sweetness, as compared to sugar, erythritol is often used in combination with other sweeteners.
Likely the biggest news in the area of natural alternative sweeteners came this December when FDA issued a no-objection letter to generally-recognized-as-safe status recognition for Rebaudioside A (Reb A). This purified component of Stevia rebaudiana, an herb in the chrysanthemum family that grows wild as a small shrub in South America, exerts varying degrees of sweetness. Reb A is said to be the sweetest, purest part of the stevia leaf. It is non-caloric and about 200 times sweeter than sugar.
Reb-A is pH stable and does not ferment, making it ideal for sweetening yogurt and frozen desserts. It can directly replace all the sugar in a product formulation, or, when used as a partial replacement, works synergistically with sugar.
Another herb-derived natural sweetener comes from the Asian fruit luo han guo, which is harvested from the Momordica grosvenori plant. Mogrosides are the source of intense sweetness in the fruit. Considered a natural food ingredient in the United States, luo han guo extracts can be about 300 times sweetener than sugar and contribute zero calories.
Thaumatin is a low-calorie flavor modifier (that’s what it is GRAS approved for in the States), which is a natural protein extracted from the West African katemfe fruit, Thaumatococcus daniellii. The ingredient is about 3,000 times as sweet as sucrose.
Finally, the most common plant-derived alternative sweetener currently being used in U.S. dairy foods is agave syrup, also sometimes called agave nectar, which is produced using wild food agave plants mostly grown in Mexico. Agave syrup contains 2.9 calories per gram and is low-glycemic. Due to its 70% fructose level, agave syrup provides a high level of sweetening with fewer calories than sucrose.