Polyols are sugar-free sweeteners. Polyols are carbohydrates but they are not sugars. They are used volume-for-volume in the same amount as sugar is used, unlike intense sweeteners like acesulfame potassium, aspartame, saccharin, and sucralose which are used in very small amounts.
Since “polyols” is not a consumer friendly term, many nutritionists and health educators refer to polyols as “sugar replacers” when communicating with consumers. Other terms used primarily by scientists are “polyhydric alcohols” and “polyalcohols”.
Those most frequently used in foods in the European Union (EU) are maltitol and maltitol syrups (E965), isomalt (E953), lactitol (E966), mannitol (E421), sorbitol (E420), xylitol (E967) and erythritol (E968).
In the European Union, they are now used in a wide range of products, including chewing gums, candies, ice cream, baked goods and fruit spreads. They are also used in toothpastes, mouthwashes, breath mints and pharmaceuticals such as cough syrups or drops and throat lozenges.
Polyols function well in fillings and frostings, canned fruits, yogurt and tabletop sweeteners. Also, some functional foods or nutraceuticals are sweetened with polyols.
Polyols provide fewer calories per gram than sugar, they do not promote tooth decay and they do not cause sudden increases in blood glucose levels. Because they taste good, people can improve the healthfulness of their diets without having to sacrifice the pleasure of eating sweet foods they enjoy.
For the vast majority of consumers, these sweeteners do not cause a problem. In some people, excessive consumption may cause gastrointestinal symptoms, such as gas or laxative effects, similar to reactions to beans and certain high-fibre foods. Such symptoms depend on an individual’s sensitivity and the other foods eaten at the same time.
Gastrointestinal symptoms, if they occur at all, are usually mild and temporary. If a person believes she/he is sensitive, the amount eaten on a single occasion should be reduced. Most people will adapt after a few days, the same way they do to high fibre foods. Many people with diabetes, for example, have learned from their health professionals to eat only a small amount of sugar-free products containing polyols at first and then to gradually increase these foods in the diet.
Polyols have been used in foods around the world for many years. The Joint WHO/FAO Expert Committee on Food Additives (JECFA) has carefully reviewed them and concluded that they are safe for human consumption. In the European Union, the Scientific Committee on Food (SCF), now the European Food Safety Authority (EFSA), like JECFA, has given the polyols an ADI “not specified” which is the highest safety rating that can be given to a food additive. This means that the polyols can be used at quantum satis ( no maximum level specified) and usage in accordance with Good Manufacturing Practice/GMP). Sorbitol, mannitol, lactitol, xylitol, isomalt, maltitol and erythritol are approved food additives in the EU.
Sugar provides approximately 4.0 kcal/g. The energy value used in current EU law for labelling purposes gives polyols the energy value of 2.4 kcal/g; the only exception is erythritol, which is given the energy value of 0 kcal/g.
Polyols are used to replace sugar on a volume-for-volume basis: they have the same technical properties than sugar, and physiological benefits.
Polyols generally do not lose their sweetness when they are heated and in foods that are heated when processed or cooked. However, unlike sugar, they do not usually give a crisp brown surface to foods which are baked. The non-browning property is an advantage for products for which a change in colour is not desired.
Polyols are slowly and incompletely absorbed from the small intestine into the blood. The portion that is absorbed is metabolized by processes that require little or no insulin. Some of the portion that is not absorbed into the blood is broken down into smaller segments in the large intestine. Erythritol differs from other polyols in that it is almost fully absorbed and not metabolized.
Polyols are hardly converted to acids by bacteria in the mouth and, therefore, do not promote tooth decay.
Because these sweeteners have lower caloric values, they may help people with diabetes achieve their weight goals. Non-cariogenic throat lozenges may also be useful if a person’s medications cause dryness of the mouth. Polyols also cause smaller increases in blood glucose and insulin levels than sugars and other carbohydrates. Therefore, snacks sweetened with them may be useful. People with diabetes should consult their physician or other health professional about the usefulness of polyols in their daily meal plan.
The polyol name or the E number and function of the polyol appear in the ingredient list.
Sweetness varies among the polyols and depends in part on the products in which they are used. They vary in sweetness from about half as sweet as the same amount of sugar to equally sweet as sugar. Sometimes combining polyols gives a more pleasant taste. Polyols are frequently combined with other alternative sweeteners, such as acesulfame potassium, aspartame, saccharin and sucralose, in sugar-free chewing gums, candies, frozen desserts and baked goods. The polyol gives these foods mild sweetness as well as the bulk and texture of sugar; the other alternative sweeteners bring the sweetness up to the level consumers expect.
Besides food, polyols are used in feedstuff including pet foods, as polyols are included in the EU Catalogue of feed materials. However, in some cases accidental consumption of foods intended for humans by certain animal species may have adverse effects on these animals. E.g. due to the physiological differences between the human and canine metabolism, an accidental consumption of food containing xylitol may be harmful to dogs.