Propyl gallate: 
 Referred to as PG. Formula (Formula): C10H12O5 MW (Molecular Weight): 212.21. White to light brown crystalline powder, or slightly milky white needle crystal. Odorless, slightly bitter, odorless solution. PG insoluble in water, slightly soluble in cottonseed oil, peanut oil, lard. The aqueous solution of 0.25% PH value of 5.5 or so. Propyl gallate relatively stable, the case of copper, iron and other metal ions color reaction, becomes purple or dark green, moisture, light and unstable, decomposition, high temperature is poor. Use a variety of foods in food consumption% PG: animal vegetable oil 0.001-0.01 0.005-0.01 0.001-0.02 whole milk bread, margarine 0.001-0.01 0.003 0.001-0.004 cereal candy gum matrix 0.1 0.01.