Sodium alginate is a natural polysaccharide derived from brown seaweed. It is widely used in the food industry as a thickener, stabilizer, and gelling agent. It is also used in the production of some pharmaceuticals and in the textile and printing industries. When sodium alginate is added to a liquid, it forms a gel-like substance that can help to thicken and stabilize the product. This makes it useful for a variety of applications, such as in the production of sauces, dressings, and dairy products.