Lactitol

What is lactitol?

Lactitol is a poorly digestible carbohydrate, namely a sugar alcohol composed of galactose and sorbitol; it is produced by hydrogenation of lactose, which is derived from whey ^[5].

Lactitol Formula

Picture 1. Lactitol structure compared to glucose

Nutrition Facts

Calories per gram = 2
Glycemic index (GI) = 5
Sweetness, relative to sucrose = 40%
Net carbs = zero

Lactitol Uses

Lactitol is used as a sweetener and texturizer in sugar-free foods, such as ice cream, chocolate, candies, baked goods, pre-prepared pasta, frozen fish, chewing gums, infant formula, medical tablets ^[1]. In the European Union it is labeled as E number E966 ^[3]. Lactitol is also allowed in Canada, Australia, Japan and some other countries ^[2-p.220].

Lactitol monohydrate syrup is used as a laxative ^[4].

Lactitol Digestion and Metabolism

Only about 2% of the ingested lactitol is digested in the small intestine to glucose and sorbitol, which are absorbed, the rest passes to the large intestine where it is fermented by colonic bacteria to gases, short-chain fatty acids (SCFA) and lactic acid, which are partly consumed by bacteria and partly absorbed ^[1,2-p.211]. Lactitol can provide 2 kilocalories per gram ^[2-p.211]. Lactitol attracts water from the intestinal wall (osmotic effect) so it can cause diarrhea if consumed in excess. According to The Scientific Comittee on Food to the EC (SCF-EC), consumption of 20 grams lactitol per day should not have a laxative effect ^[2-p.212].

Possible Lactitol Benefits

Tooth decay. Lactitol is not readily metabolized by the mouth bacteria so it does not promote dental caries ^[1,2-p.216].

Diabetes mellitus. Lactitol has a low glycemic index (GI = 5); it has a negligible effect on blood glucose or insulin levels ^{[1,2-pp.9,215]}.

Lactitol Safety

Lactitol is safe to use according to World Health Organization’s Joint Expert Committee on Food Additives (JECFA) ^[1]. In the United States, Generally Recognized As Safe (GRAS) affirmation petition for the use of lactitol in foods was accepted by the US Food and Drug Administration (FDA), which means, lactitol is allowed to be used in food products in the U.S; however, lactitol (as of y. 2014) is not yet GRAS ^[1].

Side Effect and Dangers

Lactitol in large amounts may cause bloating and diarrhea.

Lactitol and Cooking

Physical properties:

Lactitol is commercially available as a dry anhydrous lactitol or lactitol monohydrate, which contains water; both appear as white crystalline powders ^{[1,2-p.205,5]}.
40% as sweet as sucrose and has almost no cooling effect ^[1]
Not hygroscopic – does not readily attract moisture from the air ^[1,2-p.210]
Solubility in water at 77 °F (25° C) = 57 g/100 g solution ^[2-p.158]
Melting point = 295° F (146° C) ^[6]
Heat stability >320° F (>160° C) ^[2-p.158]
Does not undergo the Maillard browning reaction ^[2]