Gellan gums

Gellan Gum. GeUan gum is the generic name for the extraceUular polysaccharide produced by the bacterium. Pseudomonas elodea (ATCC 31461). Proprietary to Kelco Division of Merck Co., Inc., geUan gum is manufactured in an aerobic, submerged fermentation (76). 

Chthoniobacter flavus has been obtained in pure culture (Sangwan et al. 2004), which was made possible by the use of a dilute nutrient broth medium solidified with gellan gum in place of agar (Janssen et al. 2002), and this has since been extended (Sangwan et al. 2005). 

Wellan gum is produced by aerobic fermentation. The backbone of wellan gum is identical to gellan gum, but it has a side chain consisting of L-mannose or L-rhamnose. It is used in fluid loss additives and is extremely compatible with calcium ions in alkaline solutions. 

C. Carrageenan and gellan gum gelation mechanism and supermolecular structure... 

Gellan gum is a linear, anionic heteropolysaccharide produced by a microorganism. Most applications of gellan gum are based on its outstanding gel-forming ability in the presence of certain cations at low polymer concentrations. Gellan gum can form gels with various physical... 

Funami, T., Noda, S., Nakauma, M., Ishihara, S., Takahashi, R., Al-Assaf, S., Ikeda, S., Nishinari, K., and Phillips, G. O. (2008). Molecular structures of gellan gum imaged with atomic force microscopy in relation to the rheological behavior in aqueous systems in the presence or absence of various cations. J. Agric. Food Chem. 56, 8609-8618. 

Gellan gum with various acyl contents in the presence or absence of potassium. Food Hydrocolloids 22,1148-1159. 

There are several reports on the coating of bone-like hydroxyapatite onto natural polymer substrates. Kawashita et at. [57] reported that carboxymethylated chitin and gellan gum gels, which have carboxyl groups, can form hydroxyapatite on their surfaces in SBF if they are treated with a saturated Ca(OH)2 solution in advance, while curdlan gel, which has no carboxyl group, does not form hydroxyapatite in SBF, even if it is treated with Ca(OH)2 solution. These results support the hypothesis that carboxyl groups induce hydroxyapatite nucleation. Kokubo et at. [58,59] reported that non-woven fabrics of carboxymethylated chitin and alginate fibers also form hydroxyapatite on their surfaces in SBF if they are treated with Ca(OH)2 solution. 

Gellan Gum (Deacetylated) Kelcogel 0.6 in 0.3% Hexa-monophosphate Kelco/Merck, San Diego, CA... 

Gellan Gum Medium Induced Medium Rigid Cyclic Side Chain Strong... 

Cellulose Sulfate Chondroitin 4-Sulfate Chondroitin 6-Sulfate Dextran Sulfate Gellan Gum Gelatin A (pH = 9.0) Gelatin B (pH = 6.5)... 

Polymer Media Alginate (Sodium) Cellulose Sulfate Carboxy- methyl Cellulose Xanthan Carrageenan (A) Gellan Gum Poly Glutamic Acid... 

Gellan gum has been promoted as a suitable gelling agent for making fruit flavour jellies. It is particularly suited to this application as it is very stable even in acid conditions. 

It is claimed that gellan gum is compatible with gelatine, xanthan gum, locust bean gum and starch. 

At the time of writing gellan gum has been approved for food use in several countries. It will probably be approved everywhere in time. 

Gellan gum had a slow initial take up by the food industry. Some bakery industry uses are in pie and bakery fillings, bakery icings, frostings and glazes. Gellan gum is often used with other gums and thickeners. 

If the alkali step is removed a high acetyl gellan gum is produced. This type of gellan gum gives a more elastic thermoreversible gel similar to gelatine. This product might be more successful but it needs separate food approvals. 

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