The texture of food often matters as much as its flavor. A smooth pudding, a firm jelly, a creamy chocolate milk or a stable salad dressing all depend on ingredients that control how liquids behave. Agar, carrageenan, gellan gum and sodium alginate are four natural hydrocolloids widely used to thicken, gel and stabilize foods. Alongside them, emulsifiers and structuring agents such as glycerol...