Title: Gellan Gum
CAS Registry Number: 71010-52-1
Synonyms: Native gellan gum; high acyl gellan gum; polysaccharide S-60; PS-60
Literature References: Extracellular polysaccharide obtained by aerobic fermentation of
Pseudomonas elodea. Anionic hydrocolloid composed of acetylated linear tetrasaccharide repeat unit b-D-glucose, b-D-glucuronic acid and a-L-rhamnose in a 2:1:1 molar ratio. Prepn of native form: K. S. Kang, G. T. Veeder,
US 4326053; of deacetylated form: K. S. Kang
et al., US 4326052 (both 1982 to Merck & Co.); R. Moorhouse
et al., ACS Symp. Ser. 150, 111 (1981). Structural studies: M. A. O'Neill
et al., Carbohydr. Res. 124, 123 (1983); P.-E. Jansson
et al., ibid. 135. Gelation properties: H. Grasdalen, O. Smidsrod,
Carbohydr. Polym. 7, 371 (1987). Texture profile analysis: G. R. Sanderson
et al. in
Gums and Stabilizers for the Food Industry vol. 4, G. O. Phillips
et al., Eds. (IRL Press, Oxford, 1988) pp 219-229. Determn in food gels: J. K. Baird, W. W. Smith,
Food Hydrocolloids 3, 407 (1989); in food products: H. D. Graham,
ibid. 435 (1990). Use as agar substitute in culture media: D. Shungu
et al., Appl. Environ. Microbiol. 46, 840 (1983). Physicochemical properties: M. Milas
et al., Biopolymers 30, 451 (1990). Rheological study: P. B. Deasy, K. J. Quigley,
Int. J. Pharm. 73, 117 (1991). Comparative review of gelling agents: G. R. Sanderson
et al., Cereal Foods World 34, 991-998 (1989).
Reviews: G. R. Sanderson in
Food Gels, P. Harris, Ed. (Elsevier Appl. Sci., London, 1990) pp 201-232; W. Gibson in
Thickening and Gelling Agents in Food, A. Imeson, Ed. (Blackie Academic & Professional, London, 1992) pp 227-249.
Properties: Readily sol in water. Forms thermoreversible gels.
Derivative Type: Low acyl purified gellan gum
Synonyms: Deacylated gellan gum; deacylated PS-60
Trademarks: Gelrite (CP Kelco); Kelcogel (CP Kelco)
Properties: Unsubstituted tetrasaccharide. White to tan powder, mol wt ~0.5 ′ 106. Partially sol in cold water; aqueous dispersions dissolve >70°. Forms thermoreversible gels. Incompat with strong oxidizers. Bulk density ~50 lb/cu ft. LD50 orally in rats: >5000 mg/kg (Sanderson, 1990).
Toxicity data: LD50 orally in rats: >5000 mg/kg (Sanderson, 1990)
Use: In foods, pharmaceuticals, and personal care products as gelling, texturizing, stabilizing, film forming and suspending agent. For microbiological media and plant tissue culture.