An effective method for extracting and preparing vitamin C.

1\ The method for extracting vitamin C and 2- keto -L- gulonic acid from vitamin C mother liquor comprises the following steps: neutralizing the vitamin C mother liquor to generate vitamin C salt and 2- keto -L- gulonic acid salt to obtain a salt solution; Stirring the salt solution, cooling, and precipitating 2- keto -L- gulonate from the salt solution; Dissolving 2- keto -L- gulonic acid salt with water, removing cations with cation exchange resin, concentrating, crystallizing and separating to obtain 2- keto -L- gulonic acid; Take the salt solution of precipitated 2- keto -L- gulonate, remove the cation with cation exchange resin, and then concentrate, crystallize and separate to obtain vitamin C. This method is scientific in process, simple in operation, practical, effective in separation and high in recovery rate, which not only increases economic benefits, but also avoids environmental pollution, and has good economic and social benefits.

Date of application: May 20, 2009

Release date: 2009. 10. 14.

Patent applicant: Zhengzhou Tuoyang Industrial Co., Ltd.

Address: 45000 1, No.76 Science Avenue, High-tech Development Zone, Zhengzhou City, Henan Province.

2\ For APIs,

There are two methods to extract VC: the classic Lediger method and the two-step fermentation method widely used in China.

Lai's method is a classic method to produce vitamin C. D sorbitol was prepared from glucose by catalytic hydrogenation, and then L- sorbose was prepared with high yield by submerged fermentation and oxidation with acetic acid bacteria. L- sorbose is treated with acetone and sulfuric acid (commonly known as propionylation in production) to form diacetone -L- sorbose (abbreviated as diketone), and then extracted with benzene or toluene. Remove the extract by water method, then evaporate and separate the solvent.

The two-step fermentation method widely used in domestic enterprises, that is, after sorbitol fermentation produces sorbose, the second step of sorbose is directly oxidized by bacteria to produce 2- oxogulonic acid, and the two steps of acetone and chemical oxidation are abolished. The reaction process is the catalytic hydrogenation of glucose to produce sorbitol, the fermentation of sorbitol to produce L- sorbose, and the second fermentation to produce 2- oxogulonic acid.