Sweet-flavored substances are usually produced by compounds containing hydroxyl (-OH) or carbonyl (C=O) groups. Specifically, some common sweet aroma substances include glucose, fructose, sucrose, maltose, lactose, mannitol, propylene glycol, vanillin, vanillin, vanillic acid, and methylparaben, etc. Sundried is a flavor enhancer that is usually made from a blend of several fragrances and flavorings, and therefore may contain multiple sweet aroma substances.