Propane-1,2-diol alginate

Propane-1,2-diol alginate (also known as propylene glycol alginate or PGA) is a stabilizer, emulsifier, and thickener used in food products. It is a food additive with the E number E405. Chemically, it is an ester of alginate and propylene glycol, which is derived from seaweed.

Chemical Structure

Propane-1,2-diol alginate is a carbohydrate polymer that is composed of mannuronic acid and guluronic acid residues. It is a linear copolymer with homopolymeric blocks of (1-4)-linked β-D-mannuronate (M) and its C-5 epimer α-L-guluronate (G) residues, covalently linked together in different sequences or blocks.

Production

The production of propane-1,2-diol alginate involves the reaction of propylene oxide with alginate in aqueous solution, followed by purification and drying. The alginate is typically derived from brown seaweed (Phaeophyceae).

Uses

Propane-1,2-diol alginate is used in a variety of food and beverage applications due to its ability to improve the texture and stability of products. It is commonly used in beer to promote foam stability. It is also used in ice cream to prevent ice crystal formation, in salad dressings to provide a creamy texture, and in baked goods to increase dough yield and improve the texture of the finished product.

Safety

Propane-1,2-diol alginate is generally recognized as safe (GRAS) by the FDA. However, like all food additives, it should be consumed in moderation.

See Also

• Food additive
• E number
• Alginate
• Propylene glycol