A humectant is an additive that attracts and holds water. It is a function name: it says what the ingredient does, not exactly what it is. In packaged cakes, croissants and soft cookies, humectants keep the crumb moist and tender for months and stop fillings from drying out or cracking.
Common humectants include glycerol (glycerin, INS 422), sorbitol (INS 420), propylene glycol (INS 1520), maltitol (INS 965) and polydextrose (INS 1200). Ingredients that are not classed as additives, such as glucose syrup, honey and invert sugar, do a similar job.
The Today Croissant with chocolate, hazelnut and vanilla cream filling lists humectant at about 2.5% without naming the substance, which helps explain how a yeast pastry stays soft in its wrapper. Most humectants are made from plant sources, but glycerol can also come from animal fat, so the label alone does not reveal the origin.
