Potassium sorbate, the potassium salt of sorbic acid, with the molecular formula C6H7O2K, is a white to light yellow granules or fine powder, odorless or slightly odorous, long exposure to air is easy to absorb moisture, oxidation decomposition and discoloration. Soluble in water, soluble in propylene glycol and ethanol. Potassium sorbate has the same preservative mechanism as sorbic acid, i.e. it combines with the sulfhydryl groups of microbial enzyme systems and thus destroys the action of many enzyme systems. Potassium sorbate effectively inhibits the activity of moulds, aerobic bacteria and yeasts, and prevents the multiplication of micro-organisms such as Staphylococcus, Clostridium and Salmonella, but it is ineffective against anaerobic Bacillus and Lactobacillus acidophilus, inhibiting development more than sterilizing it, thus prolonging the shelf life of the food while maintaining its original flavor.