What Is Propyl Gallate？

2026-05-15

Contact Kerton Chemicals For A Free Quote Right Now!!

Propyl gallate (PG) has the molecular formula C₁₀H₁₂O₅, with a molecular weight of 212.21, and is a white to light yellowish-brown crystalline powder or milky white needle-like crystals. It is odorless, slightly bitter, and tasteless in aqueous solution. It is one of the important derivatives of the plant polyphenol gallic acid and is primarily used in fried foods, instant noodles, and canned foods. Its antioxidant efficacy is superior to that of the commonly used food antioxidants BHA and BHT.

Propyl Gallate Properties

Name	Propyl gallate (PG)	Odor	Odorless/Tasteless
Appearance	White to light beige powder	Vapor Pressure	0 Pa at 20 °C
Water Solubility	0.35 g/100 mL (25 °C)	Refractive Index	1.5140 (estimate)
Melting Point	146-149 °C (lit.)	Flash Point	187 °C
Boiling Point	312.03°C (rough estimate)	Solubility	50 mg/mL in Ethanol
Density	1.210	Storage Conditions	Store below +30 °C
Acidity Coefficient (pKa)	8.11 (at 25 °C)	Main Applications	Diagnostic assay manufacturing, Hematology, Histology

The Main Applications of Propyl Gallate

1. Propyl gallate is primarily used in fried foods, instant noodles, and canned foods, and its antioxidant efficacy is superior to that of commonly used food antioxidants BHA and BHT.
2. In the field of feed antioxidants, the commonly used ethoxyquin (EMQ) has now been banned in Europe, and propyl gallate is poised to replace it.
3. In 2003, China’s State Food and Drug Administration approved the production of propyl gallate (trade names: Propyl Gallate for Injection and Tongmai Zhi for Injection) for the treatment of thrombotic diseases such as cerebral thrombosis, coronary heart disease, and thrombophlebitis.

Quality Index

Assay (as C₁₀H₁₂O₅)	98.0 - 102.0 %
Melting Point	146 - 150 ℃
Arsenic (As)	≤ 3 mg/kg
Lead (Pb)	≤ 1 mg/kg
Loss on Drying	≤ 0.5 %
Residue on Ignition	≤ 0.15 %

What Is Propyl Gallate in Food?

In the food industry, propyl gallate is an important antioxidant widely used in foods such as oils, fried foods, dried fish products, biscuits, instant noodles, boiled rice, canned nuts, and pickled bacon products. Propyl gallate, as a fat-soluble antioxidant, is suitable for use in plant oils and fats. It has significant effects on stabilizing soybean oil, cottonseed oil, palm oil, unsaturated fats, and hydrogenated vegetable oils. When used in combination with a synergist, the antioxidant effect of propyl gallate is better, and the effect is also better when mixed with butyl hydroxyanisole and dibutyl hydroxytoluene than when used alone.
According to China's "Hygienic Standards for the Use of Food Additives" (GB 2760-2011), the recommended dosage of PG in these foods is 0.1g/kg (based on total fat content). PG has better antioxidant properties than other common antioxidants such as BHA and BHT and has lower toxicity and high safety when used. Therefore, it has been approved as one of the oil antioxidants by the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) of the United Nations.

Safety and Toxicity

The toxicity of propyl gallate is relatively low, with an oral LD50 value of 3600 mg/kg in rats, indicating its high safety. PG can be broken down in the body, with most of it aggregating into 4-O-methyl gallic acid or glucuronic acid and excreted through urine. However, PG is unstable to light, prone to decomposition, and undergoes a color reaction when in contact with metal ions such as copper and iron, turning purple or dark green. Therefore, copper, iron, and other metal containers should be avoided during use.