Definition:
Gellan gum is high molecular mass polysaccharide gum produced by a pure culture fermentation of carbohydrates by Pseudomonas elodea, purified by recovery with isopropyl alcohol, dried, and milled. The high molecular mass polysaccharide is principally composed of tetracyclic repeating unit of one rhamnose, one glucuronic acid, and two glucose units and is substituted with acyl group as the O-glycosidically-linked esters. The glucuronic acid is converted to potassium, sodium, calcium and magnesium salt. It usually contains small amount of nitrogen-containing compounds resulting from fermentation procedures.
Molecular mass:
Approximately 500 000
Description:
Off-white powder
Functional uses:
Thickening agent, gelling agent, stabilizer, etc
Solubility:
Soluble in water, forming viscous solution; insoluble in ethanol
Loss during drying:
Not more than 15 % (105 °C, 2.5 h)
Lead:
Not more than 2 mg/kg
Nitrogen:
Not more than 3 %
Gel test with calcium ion:
Add 1.0 g of sample to 99 mL of water, and stir for about 2 h. Draw a small amount of this solution into a wide bore pipette and transfer to a 10 % solution of calcium chloride. A tough worm-like gel will be formed immediately
Gel test with sodium ion:
To the 1 % solution of the sample, add 0.5 g of sodium chloride, heat to 80 °C by stirring and hold at 80 °C for 1 min. Allow solution to cool to room temperature. A firm gel will form
Isopropyl alcohol:
Not more than 750 mg/kg
Microbiological criteria
1. Total plate count Not more than 10 000 colonies per gram
2. E. coli Negative by test
3. Salmonella Negative by test
4. Yeasts and moulds Not more than 400 colonies per gram
Gellan gum is high molecular mass polysaccharide gum produced by a pure culture fermentation of carbohydrates by Pseudomonas elodea, purified by recovery with isopropyl alcohol, dried, and milled. The high molecular mass polysaccharide is principally composed of tetracyclic repeating unit of one rhamnose, one glucuronic acid, and two glucose units and is substituted with acyl group as the O-glycosidically-linked esters. The glucuronic acid is converted to potassium, sodium, calcium and magnesium salt. It usually contains small amount of nitrogen-containing compounds resulting from fermentation procedures.
Molecular mass:
Approximately 500 000
Description:
Off-white powder
Functional uses:
Thickening agent, gelling agent, stabilizer, etc
Solubility:
Soluble in water, forming viscous solution; insoluble in ethanol
Loss during drying:
Not more than 15 % (105 °C, 2.5 h)
Lead:
Not more than 2 mg/kg
Nitrogen:
Not more than 3 %
Gel test with calcium ion:
Add 1.0 g of sample to 99 mL of water, and stir for about 2 h. Draw a small amount of this solution into a wide bore pipette and transfer to a 10 % solution of calcium chloride. A tough worm-like gel will be formed immediately
Gel test with sodium ion:
To the 1 % solution of the sample, add 0.5 g of sodium chloride, heat to 80 °C by stirring and hold at 80 °C for 1 min. Allow solution to cool to room temperature. A firm gel will form
Isopropyl alcohol:
Not more than 750 mg/kg
Microbiological criteria
1. Total plate count Not more than 10 000 colonies per gram
2. E. coli Negative by test
3. Salmonella Negative by test
4. Yeasts and moulds Not more than 400 colonies per gram
