Xylitol

Xylitol is a five-carbon sugar alcohol, CAS 87-99-0, molecular formula C5H12O5 and molecular weight 152.15. The industrial route starts from xylan-rich biomass - hardwood such as birch, or agricultural residues including corn cobs, wheat and rice by-products. The xylan is hydrolysed to xylose and the xylose is catalytically hydrogenated, classically over a Raney nickel catalyst, then crystallised and dried. Because of that catalyst step, nickel is the signature control point on a xylitol certificate of analysis: the EU purity criteria for E967 cap it at 2 mg/kg on a dry weight basis, alongside assay not less than 98.5% xylitol on the anhydrous basis, other polyhydric alcohols not more than 1%, reducing sugars not more than 0.2% as glucose, and arsenic and lead at 3 mg/kg and 1 mg/kg respectively. Xylitol is the polyol that behaves most like sugar in the mouth. It matches sucrose for sweetness one for one, which is what makes it the default choice where a formulator wants a straight sugar swap without a high-intensity sweetener in the recipe, and it delivers 2.4 kcal/g under EU Regulation 1169/2011 against 4 kcal/g for sucrose, with a glycaemic index of about 7 on a scale where glucose is 100. It is far more soluble than erythritol at roughly 168 g per 100 g of water and melts at 92 to 96 degrees C, so it dissolves quickly in syrups, coatings and oral liquids. Dissolution is strongly endothermic and xylitol gives the most pronounced cooling perception of the common polyols, which is why it dominates mints, chewing gum, lozenges and oral-care formats. It is hygroscopic above roughly 65 per cent relative humidity, so packaging integrity and conditioned production areas matter more than they do for erythritol. Directly compressible granulated grades are available for chewable tablets and lozenges where flow and hardness have to be built in. One commercial fact must travel with every quotation: xylitol is toxic to dogs, with dose-dependent insulin release and life-threatening hypoglycaemia reported from about 100 mg per kg body weight, and signs appearing within 30 to 60 minutes. Xylitol-containing material must be excluded from pet food and pet treats, and finished human products sold in markets where the warning is expected should be labelled accordingly. On the nutrition side, the general polyol laxative-effect labelling requirement applies at higher intakes. The material is vegan with no animal input and is free of milk, egg, soy, fish, crustacean, nut and gluten sources; note that birch-derived xylitol is a wood-sourced ingredient and carries no tree-nut allergen status. Pharmacopoeial grades meeting the European Pharmacopoeia and USP-NF xylitol monographs are supplied where an excipient dossier is required.