Propylene glycol alginate

Brief Overview 

Propylene glycol alginate is an ester of alginic acid derived from large brown seaweed called kelp and represented by the E number E405. It is a white to yellowish filamentous powder available in the market and used in cosmetics. It is also widely used in the food industry as an emulsifier, stabilizer, and thickener.

Manufacturing Process

Propylene glycol alginate is made by taking moist alginic acid (20% or greater solids) that has been partially reacted with sodium carbonate and treating it with liquid propylene oxide in a pressure vessel for 2 hours at about 80°C. The product is dried and milled.

Food Industry 

Propylene glycol alginate helps prevent food components from sticking to one another and forming clumps, such as in dried soups or grated cheese. It can be used to hold food components together or thicken them during and after processing. It dissolves other processed food additives or nutrients, such as colors, flavors, or antioxidants. Propylene glycol alginate combined with xanthan gum can be used as an emulsion stabilizer for salad dressings. Another application is a dispersion stabilizer for acid milk beverages, where PGA is used to avoid precipitation.