A humectant is a food additive that attracts and holds onto water, keeping foods moist and soft. You’ll find humectants in products like shredded coconut, marshmallows, soft candies, beef jerky, and baked goods. They work by binding to free water molecules in food, which serves a dual purpose: it preserves the texture you expect and makes the food less hospitable to bacteria and mold.
How Humectants Work in Food
Every food contains water, and that water exists in two forms: water that’s chemically bound to other molecules and free water that’s available for microorganisms to use. Scientists measure that free water using a scale called “water activity.” Humectants grab onto free water molecules and hold them tightly, effectively lowering the water activity of the food. This means bacteria and mold have less available moisture to grow in, which extends shelf life without the food actually feeling dry.
At the same time, humectants improve texture. Glycerol, one of the most common humectants, plasticizes and expands protein networks in foods like jerky. That means it softens and adds elasticity to what would otherwise be a tough, chewy product. The result is food that stays pliable and pleasant to eat for much longer than it would on its own. This is why humectants are especially valuable in semi-dried products, confections, and anything that needs to stay soft on the shelf.
Common Humectants on Ingredient Labels
The two humectants you’ll see most often on food packaging are glycerin (also called glycerol) and sorbitol. The FDA lists both as moisture-retaining ingredients used in shredded coconut, marshmallows, soft candies, and confections. But the humectant family is broader than that. Here are the most common ones:
- Glycerin (glycerol): The workhorse humectant. It’s a colorless, slightly sweet liquid derived from fats or produced synthetically. It’s effective at binding water and softening protein-rich foods.
- Sorbitol: A sugar alcohol that pulls double duty as both a humectant and a low-calorie sweetener. Common in sugar-free candies, gums, and baked goods.
- Propylene glycol: Used in seasonings, frostings, frozen dairy products, and flavoring preparations. The FDA sets specific concentration limits for this one, ranging from 2% in most foods up to 24% in confections and frostings.
- Honey and molasses: Natural ingredients with strong hygroscopic (water-attracting) properties. Bakers have used honey for centuries to keep breads and cakes moist longer.
Some humectants also function as anti-caking agents, preventing powdered or granulated products from clumping together. When a humectant binds moisture at the surface of individual particles, those particles are less likely to stick to each other.
Why Food Manufacturers Use Them
Shelf life is the primary motivation. A soft cookie that dries out in two days isn’t commercially viable. Humectants let manufacturers produce foods that stay moist for weeks or months without refrigeration. This is especially important for products that sit in warehouses, travel long distances, or wait on store shelves.
Texture is the second big reason. Without humectants, many processed foods would be noticeably harder or more brittle. Marshmallows would lose their pillowy quality. Jerky would become rigid and difficult to chew. Fondant and soft candies would dry out and crack. By retaining moisture within the food matrix, humectants maintain the eating experience consumers expect.
Safety and Regulation
The humectants used in food carry Generally Recognized as Safe (GRAS) status from the FDA. Propylene glycol, for example, has specific maximum usage levels set by federal regulation. It can make up no more than 5% of alcoholic beverages, 2.5% of frozen dairy products, and 2% of most other food categories as served. These limits are based on long-standing safety data and current manufacturing practices.
Glycerin has an even longer track record of safe use and appears as a component in numerous FDA-recognized food ingredients. Neither glycerin nor propylene glycol at the levels found in food products raises significant health concerns for most people.
Digestive Effects of Sugar Alcohol Humectants
The one area worth paying attention to is sugar alcohols like sorbitol, maltitol, and isomalt. These humectants can cause digestive discomfort in a dose-dependent way. Most healthy people tolerate about 10 grams of sorbitol per day with only mild symptoms like bloating or gas. At 20 grams per day, more noticeable symptoms like abdominal pain and diarrhea become common.
This matters most with sugar-free products, where sorbitol or maltitol may be present in relatively high amounts as both a sweetener and a humectant. If you eat several servings of sugar-free candy or gum in a day, the polyol content can add up quickly.
People with irritable bowel syndrome (IBS) tend to be more sensitive. The threshold for symptoms shifts lower in IBS patients, likely because of underlying differences in gut motility and visceral sensation. Symptoms also worsen when polyols are consumed alongside other carbohydrates, which is common in real-world eating. If you follow a low-FODMAP diet, sugar alcohol humectants are among the ingredients you’d want to monitor on labels.
How to Spot Humectants on Labels
Humectants won’t always be labeled with the word “humectant” on the package. Instead, look for specific ingredient names: glycerin, glycerol, sorbitol, mannitol, propylene glycol, or polydextrose. In more natural products, honey or molasses may serve the same function without being identified as a humectant. European food labels sometimes use E-numbers: glycerol is E422, sorbitol is E420, and mannitol is E421.
If you’re reading a label and see one of these ingredients in a product that’s meant to stay soft or moist, that’s the humectant doing its job. It’s one of the more straightforward categories of food additives, with a clear purpose you can taste and feel in the texture of the food itself.