Amino sugars

Carbohydrates carrying an amino group in place of a hydroxyl, most commonly at the carbon-2 position. Galactosamine and glucosamine are the textbook examples — structural units of chitin, bacterial cell walls and the glycosaminoglycans of connective tissue. Food chemists know a less obvious member, furosine, as a sensitive marker of the Maillard reaction in dairy products: it forms from the Amadori products of lactose–lysine reactions, so measuring it reveals how much heat damage milk powders or UHT milk have suffered. Amino sugars thus link carbohydrate chemistry to protein quality assessment in processed foods.