Alginate

Thickening agents, foam stabilizer: Ice cream, cheese, candy, yogurt, beer.
Alginate, an apparently safe derivative of seaweed (kelp), maintains the desired texture in dairy products, canned frosting, and other factory-made foods. Propylene glycol alginate, a chemically-modified algin, thickens acidic foods (soda pop, salad dressing) and can stabilize the foam in beer.