When adding sweetness to foods and beverages, many ingredient options exist.
By Claudia Dziuk O’Donnell
Unlike the bitterness of coffee or the heat of peppers that people must learn to like, the preference for sweet products is innate among most mammals. It is theorized that this desire for sweetness gave a survival advantage to early man since sugars provide a quick source of energy. Fruits, for example, can contain significant amounts of energy (calories) in the form of sugars. The U.S. Department of Agriculture’s searchable online database of food compositions (http://www.nal.usda.gov/fnic/foodcomp/search/) lists the total sugar content of raw pears as 9.8% (this is comprised 0.8% sucrose, 2.8% glucose and 6.2% fructose), bananas as 12.2% total sugars (2.4% sucrose, 5.0% glucose, 4.9% fructose), and dates (Deglet noor) as 63% total sugars (24% sucrose and 20% each of glucose and fructose). Indeed removal of water from fruits creates concentrated sources of natural sweeteners that food and beverage formulators can use. Examples include raisins and dried plums, other dehydrated fruits and fruit juice concentrates. For example, apple juice concentrate’s total sugar content is 38.8% and dried pears’ sugar content is 62.2%.
As desirable and natural as these sugars are, many consumers want products with lower levels of sugars. Thus food manufacturers use alternative ways to sweeten products.
To Your Health
In recent years, there have been a growing number of overweight and diabetic consumers the world over. The United State’s Center for Disease Control (CDC) reports that 23.7% of white, non-Hispanic people are obese, 28.7% of Hispanics and 35.7% of non-Hispanic blacks. (http://www.cdc.gov/mmwr/PDF/wk/mm5827.pdf) If you include those that are merely overweight, but not obese, nearly two-thirds of the adult U.S. population weights too much. The CDC and World Health Organization (WHO) defines obesity by Body Mass Index (BMI), calculated as weight in kilograms divided by the square of the height in meters (kg/m2 ). A BMI of 25 up to 30 means one is overweight; a BMI of 30 or means one is obese.
Being obese or overweight poses a major risk for chronic diseases such as type 2 diabetes, the world over. For example, a 2009 study of 11,550 adults in seven Latin American Countries found that overall prevalence of diabetes in all adults was 7.0%. Of those 55-64 years in age, anywhere from nine to 22% were diabetic depending on factors such as region and age. Another three to 6% were pre-diabetic. (Escobedo, J, et al. 2009. Diabet Med. 26:864-71.) The American Diabetes Association says 7.8% of the U.S. population (10.7% of those 20 years and over) in 2007 was diabetic. Additionally, it has been estimated that over 40% of the U.S. population are diabetic or pre-diabetic. (Cowie, CC, et al. Diabetes Care. 32:287-94). Worldwide, rates are expected to continue to greatly increase and consumers are worried.
According to a 2008 HealthFocus Trend Study, 38% on average of global shoppers in the 18 countries surveyed say they are extremely or very concerned about diabetes. Some 43% of U.S. consumers and 34% of Canadians express that level of concern, while 57% of Brazilians and 54% of Mexicans do so.
For these populations, it is important and even critical to control calorie intake or to minimize the consumption of foods that cause a spike in glucose blood levels. However, when sugars are removed from formulas, the sweetness they contributed must be obtained somewhere else.
A Multiple of Sweet Offerings
The ability to taste sweetness is genetic. Simply put, the perception of sweetness is initiated when a sweetener compound stimulates a receptor found in the plasma-membrane of a taste cell. More technically, there are “G protein-coupled receptors” on the tongue that are formed from two proteins called T1R2 and T1R3. When either protein is mutated or missing, sweetness perception is altered, or not perceived at all. The domestic cat does not have a functional T1R2 protein and cannot taste sweetness. New World primates such as marmosets, howlers and spider monkeys can’t perceive aspartame’s sweetness, while humans and baboons can.
Thousands of different molecules taste sweet to humans. Examples include saccharin, dulcin and acesulfame-K; many aldehydes and ketones; amino acids such as alanine, glycine and serine; and proteins such as thaumatin and lysozyme. Other commercially available sweeteners include neotame, alitame, many polyols (erythritol, sorbital), neohesperidin dihydrochalcone (NeoDHC) and a growing number of “natural” sweeteners, although the word “natural” is generally not defined by most regulatory authorities including those in the U.S.
Examples of sweeteners that have positioned themselves as natural include stevia (e.g. plant extracts with high levels of steviol glycosides such as rebaudioside-A), agave syrup and lo han guo. A number of suppliers have notified the U.S.’s FDA of the self-affirmed GRAS status of their stevia-based sweetener. Stevia is currently used primary in North and South American and Asia, according to Mintel International’s Global New Product Database (GNPD). Both stevia and agave are from plants native to South America. Lo han guo, also under consideration by the FDA, is from an Asian plant.
Table sugar (sucrose) has a set of difficult-to-replicate physical and chemical properties. Just a few include freezing point depression, which is why ice cream is still soft below the freezing point of water; delayed starch gelation, allowing baked goods more time to rise before setting; and reduction of water activity, which increases the microbial stability of jams and jellies.
Sucrose also has a fairly unique taste profile with little or no bitter, salty or metallic notes. All sweeteners also have specific sweetness temporal profile, meaning they differ in how quickly, intensely and for how long the sweetness is perceived over time. Often alternative sweeteners are blended with each other in order to better replicate sucrose’s taste. For example, aspartame’s sweetness has a slower onset and longer duration than that of sucrose and it is often blended with acesulfame K, which in turn is also is often blended with sucralose. Blends also help reduce or eliminate bitter or metallic tastes.
Formulating foods that possess a desirable taste, appearance and pleasure yet that can also assist with certain health issues has been made easier due to the many options of sweeteners now available.
Claudia Dziuk O’Donnell is chief editor of Prepared Foods magazine.
Relevant Links
To see a Spanish version of this article, click here.
August 2009 Prepared Foods cover story on sweetener issues
Related E-dition news
Ace-K and Sorbitol on Radical Formation
Heart Group Wants Sugar Limit
Rat Study: Fructose Impairs Memory
Studying Glucose, Fructose
New Class of Low-sugar Drinks Proposed
NBC: Little Difference Between HFCS and Sugar
Understanding Fructose and Human Metabolism
From the January 4, 2010, Prepared Foods E-dition
