Sweetener Blends With Erythritol

Reducing sugar in the human diet is one of the most-prominent topics worldwide, and is immediately apparent while reviewing modern nutrition’s effect on civilization. As the 21st century begins, the number of overweight, obese and malnourished people is rising steadily. Meanwhile, overweight and obese individuals far outnumber the starving; even in areas of the world where very traditional diets and eating habits are followed (e.g., Asia), the rate of overweight people has reached new dimensions.

Sweet facts

Sugar has always been a major part of human nutrition. The term "sugar" usually refers to sucrose, which is produced mainly from sugar cane or sugar beet in a number of varieties to fit the requirements of the food industry.

Another ingredient commonly referred to as sugar is corn syrup. The variety used most often is high-fructose corn syrup (HFCS). This starch derivative is sweeter than sucrose, so less HFCS will achieve the same sweetness. This is because fructose, which has a sweeter taste, makes up a larger portion (up to 90%) of HFCS than glucose and other constituents. Sugar and HFCS have no difference in caloric content; both supply 4 kcal per gram. For sweetening, sugar and sweet corn syrups are today’s benchmark for taste, availability, pricing and technical properties.

The main goal of sugar replacement or reduction in food and beverages is reducing calories provided by simple carbohydrates (mono- and disaccharides). Many different, readily available options can reduce calories. One tremendously versatile group of products that fits perfectly into reduced-sugar or sugar-free applications is the sugar alcohols.

Sugar alcohols, or polyols, have long been used in the food industry to replace the function and flavor of well-established sugars in a wide range of applications. They are grouped together based on similar chemical structure, but have very different properties. They share one common feature: At a lower caloric content than sugar, they present an attractive sweetness close to the sugar level. This valuable property will allow them to play an extraordinary role in 21st-century nutrition.

The group of polyols that includes sorbitol, maltitol, isomalt, xylitol, mannitol and lactitol has recently been extended with erythritol. Its clean sweet taste, which is very close to sugar, and its very low calorie content (0.2 kcal per gram) make erythritol an excellent choice for sugar replacement. Erythritol is 30% less sweet than sugar (measured in an aqueous solution in the same concentration), but in an application, erythritol’s real sweetness varies between 60% to 80%.

Erythritol’s high laxation threshold, glycemic index of nearly zero and clean taste set it apart from other polyols. These unique properties mainly result from the erythritol molecule’s low weight. It is the only polyol with 4 carbons in the chain where other polyols have 5 to 12 carbons, creating distinct differences in molecular weight and sizes: 122 grams per mole for erythritol compared to 184 grams per mole for a 5-carbon-bodied xylitol and 344 grams per mole for 12-carbon maltitol. The molecular size is one decisive factor determining the polyols’ fate in the human digestive tract. Erythritol’s small molecular size leads to quick absorption in the upper digestive tract, so little erythritol reaches the lower digestive tract. The lower digestive tract is where polyol degradation and osmotic effects lead to gastric distress. While this feature is linked to polyols in general, with erythritol, the effect is minimal. The smaller molecule also explains why the effective calorie content is only 0.2 kcal per gram.

One other very important point of differentiation: Like sugar, erythritol is natural. It is typically found in foods like grapes, soy sauce, wine and even in honey or cheese. Erythritol is the only sugar alternative produced by a natural microbial fermentation process.

While erythritol’s advantages in energy-reduced or sugar-reduced products are convincing, the sweetness performance may need adjustment. Studies have proven that consumers will rarely sacrifice taste for a health benefit. Sweetness is essential to the taste, so product development is needed to combine the positive effects of erythritol and additional sweetness in the finished product.

The options for adding sweetness to strengthen erythritol sweetness are numerous. Many options exist based on taste, labeling considerations, energy content or additional health benefits.

"Natural" preferred?

Erythritol works great in all-natural and organic products, because it fits perfectly into the trend of ingredients originating in nature and using natural processes to make them. In contrast to "organic," no valid legal definition exists for the term "natural." However, guidelines can help to identify what can be considered "natural"—e.g., from the United Kingdom’s Food Standards Agency—and might include erythritol, as well as inulin, fructose and, of course, regular sugar.

Although some are concerned about HFCS’s fructose, it has an interesting metabolic behavior that suits it as a natural sweetener together with erythritol. Fructose is metabolized independently from insulin and has a much slower impact on blood sugar levels, making it suitable for diabetics, like erythritol. Since fructose’s sweetness is about 120% compared to sucrose, it can increase sweetness in low amounts.

Inulin and fructooligosaccharides create valuable blends with erythritol. Inulin sweetness is not the criterion, since it is less than 30% sugar equivalent. But it offers another benefit—a positive heat of solution. This gives a warming effect upon dissolution vs. the cooling effect erythritol and other polyols show upon dissolution. For many foods, the cooling effect is not suitable. For example, milk chocolate with erythritol offers a distinct cooling effect. But combining inulin and erythritol can reduce or eliminate the cooling effect and raise the chocolate’s flavor quality significantly. As an additional highlight, inulin is also a nondigestible fiber and prebiotic that promotes growth of probiotic flora, which leads to an overall improvement in digestion.

Erythritol and sugar blends lead to products with a very high taste potential. Sugar delivers the original sweetness, and erythritol reduces the calories. Blends up to a ratio of 80% erythritol and 20% sugar provide excellent sweetness and have a calorie level about 75% below that of sugar.

High-intensity sweeteners

The advantages of high-intensity sweeteners are easily recognizable: no calories (nonnutritive) and an extraordinary sweetening power. Their enormous sweetening capacity is ideal to increase the sweetness of erythritol products. Only small amounts of aspartame, acesulfame potassium or sucralose are needed to close the sweetness gap. Such blends create a synergy, since erythritol and aspartame or acesulfame potassium reinforce each other’s sweetness. The sum of sweetness is higher than the individual sweetness of each part. This leads to an interesting savings potential in absolute amounts for certain sweetness effects. Furthermore, erythritol can reduce or eliminate the aftertaste of high-intensity sweeteners, plus add mouthfeel as a bulking agent.

Erythritol plus other polyols

Sorbitol and maltitol have revolutionized sugar-free products. Their uniqueness is based on reduced calorie load and sweetness from 50% to 100% of sugar. As these polyols have different properties, blends are more common than single polyols, since it allows fine-tuning of different parameters. All polyols cause gastric distress upon overconsumption, but scientific evidence shows erythritol is much less laxative than all other polyols. Blending it with other polyols leads to significant improvements in overall taste impression, fermentation origin ("natural"), laxative effect, glycemic index (suitable for type 2 diabetics) and hygroscopicity.

Erythritol is also a valid alternative to xylitol, with its recent weak availability and price increases. Xylitol is popular in chewing gum and candy because its benefit for the teeth goes beyond polyols’ normal tooth friendliness; it reduces plaque and oral bacteria count. Research shows erythritol has a similar effect ("Similarity of the Effects of Erythritol and Xylitol on Some Risk Factors of Dental Caries," Caries Research, 2005; 39(3):207-215). In addition to the same cooling effect (which fits well in chewing gum and candy), it offers a much higher laxation threshold and lower hygroscopicity than xylitol. The latter increases the shelf life stability.

Using erythritol in combination with other sweeteners opens a wide range of advantages and features: natural sweetening, improved taste, low-glycemic-index sweetness, etc. Though only sugar tastes exactly like sugar, using erythritol helps find the original taste without sugar addition. The quality and performance of a sweetener blend may depend on other factors like technical properties or product strategy, but one thing is certain: Taste and sweetness will make the difference.

Ferid Haji, product manager, erythritol, at bioingredients company Jungbunzlauer, Basel, Switzerland, is a food technologist who joined Jungbunzlauer in 2001, taking over erythritol responsibility in 2005. Erythritol is part of HealthyChoices@Jungbunzlauer which stands for Jungbunzlauer’s new portfolio of ingredients addressing the top health trends: mineral fortification, sugar replacement and salt substitution.