Preparation method of erythritol

The production of erythritol can be divided into two methods: microbial fermentation and chemical synthesis.
Microbial fermentation method
The fermentation method for producing erythritol began in the 1990s and has been widely used internationally for mass production of erythritol. The carbon sources for producing erythritol include alkanes, monosaccharides, and disaccharides. Glucose, fructose, mannose, and sucrose are all good carbon sources for producing erythritol, with D-mannose having the highest conversion rate, reaching 31.5%. However, due to cost factors, it mainly uses starch raw materials such as wheat or corn to produce glucose through enzymatic degradation, which is fermented by high permeability resistant yeast or other strains. Erythritol can be produced by Candida, Saccharomyces bulgaricus, Trichosporomyces, Saccharomyces triangularis, Pichia Saccharomyces, etc. The industrial production process of erythritol fermentation method is as follows: starch → liquefaction → saccharification → glucose → fermentation of production strains → filtration → chromatography separation → purification → concentration → crystallization → separation → drying, finally obtaining erythritol with an average yield of about 50%. The research shows that the erythritol fermentation method is affected by many factors, such as the change of osmotic pressure significantly affects the formation of polyols, the inorganic salts Mn2+and Cu2+can improve the yield of erythritol, and oxygen and temperature affect its yield. Compared with chemical synthesis, the fermentation method has more advantages in production.
Chemical synthesis method
The chemical synthesis method can be achieved by reacting butene glycol with hydrogen peroxide, then mixing its aqueous solution with an active nickel catalyst and adding the inhibitor ammonia water. Hydrogen gas is introduced at around 0.5MPa and hydrogenated to obtain erythritol products. However, the production efficiency of the chemical method is low and industrial production has not yet been achieved.