Potassium sorbate, also known as potassium 2,4-hexadienoate, is the potassium salt of sorbic acid, with the molecular formula C6H7O2K, white to light yellow scale crystals, crystal particles or crystal powder, odorless or slightly odorous, long-term exposure to air Easy to absorb moisture, be oxidized and decomposed to change color. Soluble in water, soluble in propylene glycol and ethanol. Often used as a preservative.