Propylene glycol alginate

Propylene glycol alginate (CAS 9005-37-2), commonly abbreviated as PGA and approved as E405, is a modified alginate ester derived from alginic acid. Unlike standard alginates, it remains stable and functional in acidic conditions.

This unique stability makes it a preferred thickener and emulsifier in formulations where pH control is critical. In food and beverage production, PGA stabilizes salad dressings, sauces, and acidic beverages by preventing phase separation.

It maintains viscosity at low pH levels effectively. Brewers use it to improve and sustain foam head stability in beer, which is a specific performance requirement that few other hydrocolloids can meet effectively.

Pharmaceutical manufacturers incorporate it into liquid oral dosage forms and topical gels where controlled rheology and acid tolerance are both required. It ensures consistent delivery and texture in medical applications.

In personal care, it functions as a thickener and film-former in lotions and hair care products formulated at lower pH values. Propylene glycol alginate is supplied as a cream to white powder in varying particle sizes.

Standard grades include food-grade (FCC compliant) and pharmaceutical-grade material meeting USP or Ph.Eur. specifications. These quality standards ensure the material is suitable for highly regulated industries.

The degree of esterification varies by grade, directly affecting acid stability and emulsification performance. This is a key parameter buyers should confirm against their specific application requirements for optimal results.