General Description
Almost odorless fluffy, white to off-white crystalline powder. Used as an antioxidant and preservative.
Reactivity Profile
SODIUM ERYTHORBATE(6381-77-7) may be sensitive to prolonged exposure to light. Incompatible with strong oxidizing agents .
Air & Water Reactions
Water soluble.
Fire Hazard
Flash point data for this chemical are not available; however, SODIUM ERYTHORBATE is probably combustible.
Chemical Properties
Sodium erythorbate is a white to yellow-white crystalline powder or granules that are slightly salty and almost odorless. It is stable in the dry state but can deteriorate when exposed to air, trace metals, heat and light in solution. The compound has a melting point above 200℃ (decomposition) and is soluble in water (17g/100m1) but almost insoluble in ethanol. The pH of a 2% aqueous solution ranges from 5.5 to 8.0.
Preparation
It is produced through using D-glucose fermentation of Pseudomonas fluorescens Kl005 or Arthrobacter globiformis K1022 to produce 2-keto-D-gluconic acid (or calcium salt), followed by being esterified, transformed and refined. The composition of the fermentation medium is: glucose: 18; yeast extract 0.3; K2HPO4 ? 3H2O: 0.05; KH2PO4: 0.05; MgSO4 ? 7H2O: 0.025,;CaCO:34.5. The fermentation temperature is controlled at 30~35 ℃, the fermentation period is 30h, and the fermentation conversion ratio (%) is 79.9%. The fermentation broth is supplemented with sulfate and activated carbon for acidification and decoloring, followed by pressurized filtrate to obtain the clean liquid with a yield of 96.6%.
The purified fermentation broth was concentrated by decompression, and methanol and sulfuric acid were added for refluxed esterification of 5h, followed by frozen and centrifuged filtering to obtain methyl ester with a yield of 82.1%. The methyl ester was transformed with basic methanol solution under refluxing conditions, and the product was further frozen and crystallized to dryness to obtain the crude product of D-isoascorbic acid. The conversion yield was 87.3%, and it was dissolved in hot water and decolorized with activated carbon. The filtrate is pressurized filtrated and the supernatant liquid is frozen, crystallized, centrifugalized, washed and vacuum dried to obtain finished product.
The mother liquid is recovered and the yield is 88.0%.
Flammability and Explosibility
Nonflammable
