Sodium benzoate is a kind of white granular or crystal powder, odourless or microstrip benzoin odor, taste sweet, the smell of convergence. Also known as benzoic acid sodium, relative molecular mass of 144.12. Stability in the air, soluble in water, its aqueous solution PH value of 8, soluble in ethanol. Benzoic acid and its salts is a broad-spectrum antimicrobial agents, but its antimicrobial effectiveness depends on the PH value of food. As the medium acidity has increased its bactericidal, bacteriostatic efficacy enhancement, in alkaline medium, sterilization and bacteriostasis lost. The anticorrosive optimum PH value of 2.5 ~ 4.0