Mannitol is a polyol (sugar alcohol) widely used in the food and pharmaceutical industries because of its unique functional properties. It is about 50% as sweet as sucrose and has a desirable cooling effect often used to mask bitter tastes. Mannitol is non-cariogenic and has a low caloric content. Mannitol is suitable for ingestion and has been used safely around the world for over 60 years.
Mannitol is found in abundance in nature, particularly in exudates from trees, and in marine algae and fresh mushrooms. It is an isomer of sorbitol and is typically produced today by the hydrogenation of specialty glucose syrups. Mannitol is commercially available in variety of powder and granular forms.
- Reduced-calorie sweetener with only 1.6 calories per gram
- It is nonhygroscopic
- Provides sweetness with a clean, cool pleasant taste
- May be a useful alternative sweetener for people with diabetes
- Does not contribute to the formation of dental caries
The EU Nutrition Labeling Directive states that sugar alcohols, including lactitol, have a caloric value of 2.4 calories per gram. The US Food and Drug Administration allows the use of 1.6 calories per gram for mannitol.
Unlike sorbitol, a polyol often used for its humectant properties, mannitol is nonhygroscopic (does not pick up moisture). For this reason, it is often used as a dusting powder for chewing gum to prevent the gum from sticking to manufacturing equipment and wrappers. Due to its high melting point (165-169° C), mannitol is also used in chocolate-flavored coating agents for ice cream and confections. It has a pleasant taste, is very stable to moisture pickup and does not discolor at high temperatures, which makes mannitol ideal for use in pharmaceuticals and nutritional tablets.
Beneficial to People with Diabetes
The control of blood glucose, lipids and body weight are three major goals in diabetes management. Mannitol is slowly absorbed from the intestinal tract. Therefore, when mannitol is used, the rise in blood glucose and demand for insulin is much less than would be experienced after sucrose ingestion. The reduced caloric value of mannitol compared to sucrose (1.6 vs. 4.0 calories per gram) is consistent with the objective to control caloric intake and body weight in people with diabetes. Products sweetened with mannitol in place of sugar may be useful in providing a wider variety of reduced calorie and sugar-free choices to people with diabetes.
Recognizing that diabetes is complex and requirements for its management may vary between individuals, the usefulness of mannitol should be discussed between individuals and their health care providers. Foods sweetened with mannitol may contain other ingredients that also contribute calories and other nutrients. These must be considered in meal planning.
Does Not Promote Tooth Decay
Polyols, such as mannitol, are resistant to metabolism by oral bacteria and do not increase the acidity of the mouth after ingestion. This means that they will not lead to cavities or erode tooth enamel. The usefulness of polyols (including mannitol) as alternatives to sugars and as part of a comprehensive program including proper dental hygiene has been recognized by numerous authorities, including the American Dental Association. The Food and Drug Administration has approved the use of a “does not promote tooth decay” health claim in labeling for sugar-free foods that contain polyols, including mannitol. Products sweetened with mannitol may be labeled safe for teeth in other parts of the world.
How the Body Uses Mannitol
Mannitol, like all polyols, is a low digestible carbohydrate that is only partially absorbed from the small intestine and not metabolized. In the lower part of the intestinal tract, colonic bacteria metabolize some of the non-absorbed portion. In some people, this may occasionally cause softer stools or more intestinal gas than usual, similar to the effects of complex carbohydrate foods such as beans or prunes.
A person’s response to low digestible carbohydrates varies depending on individual factors such as amount and frequency of consumption. The U.S. Food and Drug Administration’s regulation for mannitol requires the following label statement for foods whose reasonably foreseeable consumption may result in the daily ingestion of 20 grams of mannitol: “Excess consumption may have a laxative effect.” Mannitol is used in very small amounts in foods so the few people who may be sensitive usually have no problem if they gradually increase their consumption of low digestible carbohydrates.
The use of mannitol in food is broadly permitted by FDA food additive regulations (21 CFR 180.25). The Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA) has reviewed the safety data and concluded that mannitol is safe. JECFA has allocated a temporary Acceptable Dietary Intake of 0-50mg/kg. Mannitol has monographs in the United States Pharmacopoeia/National Formulary (USP/NF), Codex Alimentarius, as well as the various pharmacopoeias around the world. Mannitol is included in the Food Chemical Codex (FCC).
Multiple Ingredient Approach to Calorie Control
Mannitol works well with other ingredients and may be synergistic with other sweeteners. The combination of sweeteners is often sweeter and better tasting than individual sweeteners. These blends provide taste, economic, and stability advantages.