Sodium diacetate, C4H7O4Na·xH2O, is a free flowing, acidic sodium salt widely used as food flavoring, preservative, and pH buffer. The compound consists of acetic acid and sodium acetate, chemical formula symbol NaH.
As a food flavoring agent sodium diacetate is most often used to impart a vinegar flavor in snacks, breads, and soups.
As a preservative, it can effective in preventing the development of several mold strains and is also used as an antibacterial agent to prolong the shelf life of many food types. Recent studies also suggest that sodium diacetate is an effective microbial inhibitor and pH regulator in meat and poultry products.