Propylene Glycol Alginate

Functions
Binder
Viscosity controlling agent
Emulsifier
Film-forming agent
Delivery vehicle
Gelling agent
Liposome forming agent
CAS Number(s)
9005-37-2
FDA UNII
26CD3J2R0C
INCI name
Propylene Glycol Alginate

Propylene Glycol Alginate (PGA) is a general name of 1,2-propane-diol esters with alginic acid (algin), usually obtained from Laminaria or Macrocystis species of brown seaweeds after a series of purification steps. PGAs are common food additives, marked as E405, with emulsifying, thickening, and gel-forming properties.

Esterification with propylene glycol improves algin properties, making it a universal ingredient for hydrocolloid systems. It allows formulators to achieve stable emulsions, gels, and film-forming applications. It also enables the formation of nanoparticles and forms complexes with various active ingredients, playing a crucial role in delivery systems.

The surface activity, rheological properties, and gelling potential of different Propylene Glycol Alginates depend on the degree of esterification. Changing the ion balance or adding urea to PGA-based systems can also help control the formulation's physical and sensory properties.

Combined with other polysaccharides like Xanthan gum, Propylene Glycol Alginate from more stable emulsions enables the loading of pure soluble ingredients like Calcium carbonate or hydrophobic carotenoids like Lutein. It also helps to solubilize proteins from gels in aqueous media.
See also
Synonyms
PGA
Changed

References

  1. A comprehensive review of propylene glycol alginate in the food industry: Synthesis, safety, composite hydrocolloids and application
    Author(s):
    , , ,
    DOI:
    10.1016/j.tifs.2025.104900
  2. The presence of propylene glycol alginate increased the stability and intestine-targeted delivery potential of carboxymethyl starch-stabilized emulsions
    Author(s):
    , ,
    PMID:
    35761643
    DOI:
    10.1016/j.foodres.2022.111387
  3. pH-driven self-assembly of alcohol-free curcumin-loaded propylene glycol alginate nanoparticles
    Author(s):
    , , , ,
    PMID:
    34920055
    DOI:
    10.1016/j.ijbiomac.2021.12.025
  4. Propylene glycol alginate-based film activated by Spirulina (Arthrospira platensis) powder: Physicochemical, microstructural, and functional properties
    Author(s):
    , , ,
    PMID:
    41213372
    DOI:
    10.1016/j.ijbiomac.2025.148845
  5. Propylene glycol alginate (PGA) gelled foams: A systematic study of surface activity and gelling properties as a function of degree of esterification
    Author(s):
    , ,
    DOI:
    10.1016/j.foodhyd.2016.01.011
  6. CaCO3 loaded lipid microspheres prepared by the solid-in-oil-in-water emulsions technique with propylene glycol alginate and xanthan gum
    Author(s):
    , , , , ,
    PMID:
    36071930
    DOI:
    10.3389/fnut.2022.961326
  7. Stability of lutein in O/W emulsion prepared using xanthan and propylene glycol alginate
    Author(s):
    , , , ,
    PMID:
    32084481
    DOI:
    10.1016/j.ijbiomac.2020.02.162