A crude lactide in a solid state or in an at least partially molten state is brought into contact with ethanol to form a slurry mixture, and then a solid form this slurry mixture is separated to yield a purified lactide having a high purity. A crude lactide is recrystallized from a non-denatured or denatured ethanol to obtain a lactide for a food additive. A lactide is applied widely to food additives. A coagulating agent for an animal and/or vegetable protein containing an optically active lactide as a main component, a food foaming agent containing a lactide as a main component, a food preservative containing a lactide as a main component and a pH regulating agent containing a lactide as a main component are provided.