Humectants are the reason a cake stays soft and dried fruit stays chewy. The category is small, and it contains one ingredient that appears on a very large number of labels and one question that comes with it.
The sugar alcohols
Most humectants are sugar alcohols, produced by processing plant carbohydrates.
- Sorbitol (E420): from glucose.
- Mannitol (E421): from carbohydrate sources.
- Maltitol (E965): from starch.
- Xylitol (E967): from plant xylan, such as birch or corn.
These double as sweeteners, which is why they also appear in the sweeteners guide. Either way, they are plant derived.
Glycerol, the one to check
Glycerol, listed as E422, glycerin, or glycerine, is the most widely used humectant and the one that carries a source question.
Commercial glycerol is not manufactured for its own sake. It is recovered as a by-product when fats and oils are split, including during soap manufacture and biodiesel production. Those feedstock fats may be vegetable oils or animal fats, and the finished glycerol is chemically identical either way.
A label that specifies vegetable glycerin has answered the question. One that says glycerin or E422 alone has not.
Where you will find it
Glycerol appears far beyond the humectant role. It is a carrier for flavours and colours, a softening agent in confectionery and chewing gum, a component of capsule shells, and a solvent in supplements and extracts. That breadth is why it turns up on so many of the guides on this site.
The halal chewing gum checker and the halal supplement checker both cover it in context.
What to ask the manufacturer
Please confirm the origin of the glycerol or glycerin used in this product. Is it derived from vegetable oil or animal fat, and if animal, from which species? Is this product covered by a current halal certificate in my market?
Frequently asked questions
Are humectants halal?
Most are. The sugar alcohols such as sorbitol and maltitol are made from plant carbohydrates. Glycerol, E422, is the exception, since it is recovered from fat processing and may be plant or animal derived.
What does a humectant do?
It holds moisture in a product, keeping cakes soft, dried fruit pliable, and confectionery from hardening.
Is glycerol the same as glycerin?
Yes. Glycerol, glycerin, and glycerine are names for the same substance, listed as E422.
Is sorbitol halal?
Sorbitol, E420, is a sugar alcohol produced from glucose, which comes from starch. It is plant derived.
Where does commercial glycerol come from?
It is recovered as a by-product of fat and oil processing, including soap manufacture and biodiesel production. Those fats may be vegetable or animal, which is why the source needs confirming.
Does vegetable glycerin solve the question?
A label that specifically says vegetable glycerin answers the source question for that ingredient. A label that says only glycerin or E422 does not.