Treatment for D-sodium ascorbate industrial wastewater by combined biotechnology;

2-Keto-D-gluconic acid(2KGA),usually prepared by fermentative oxidation of D-glucose,is the precursor used in the manufacture of sodium erythorbate or erythorbic acid as a food antioxidant.

The effects of various filtration materials used in the purification of sodium erythorbate on product quality were investigated.

However,combined use of SO2 and sodium ascorbate could achieve satisfactory anti-oxidation effects.

The results show that: adding antioxidant sodium ascorbate 2g/L and colour aids nicotinic amide 0.

Five long-chain saturated alkanoyl-6O-D-isoascorbates(alkanoyl=decanoyl,lauroyl,myristoyl,palmitoyl and stearoyl) were synthesized by esterification(or transesterification) of D-isoascorbic acid with alkanoic acids using concentrated H_2SO_4 as a medium and a catalyst at room temperature.

Seven n-alkyl aldehyde acetals of D-isoascorbic acid(3a～3g) were synthesized by the reaction of D-isoascorbic acid with n-alkyl aldehyde using p-toluene sulfonic acid as a catalyst, dimethyl acetamide as a solvent, cyclohexane as a water carrying agent.