1. Direct extraction method

Xylitol was first isolated from the bark of oak trees by German scientist Hermann Emil Fischer in 1890. Xylitol naturally exists in plant-based raw materials in nature, such as strawberries, yellow plums, cauliflower, and other fruits and vegetables (300-935 mg/100 g dry weight). Solvent extraction can be used to directly extract xylitol from plant-based materials, but the content of xylitol is low in plant-based materials such as fruits and vegetables. Although the content of xylitol in apricot plums is higher than other plant-based materials, and the content of xylitol in green plums accounts for about 1% of dry weight, directly extracting xylitol from them requires specialized equipment, consumes huge energy, and has high production costs.

2. Chemical synthesis method

In the 1970s, Finland was the first to use chromatography to separate D-xylose from various woody hemicelluloses. Subsequently, D-xylose was reduced to xylitol under high temperature, high pressure, and hydrogen catalysis, and developed into an industrial xylitol production method.

Xylitol can be directly reduced to pure D-xylose through chemical synthesis, or synthesized from lignocellulosic biomass rich in xylose. The production of xylitol both domestically and internationally often uses raw materials rich in pentose polysaccharides, such as natural wheat straw, wheat, corn stover, corn cob, etc., which are pretreated by acid hydrolysis (such as HCI, HSO), and then purified from hemicellulose fractions. Under the action of a catalyst, the xylose undergoes hydrogenation reaction.

3. Biological transformation method

The biotechnology route involves the hydrolysis of agricultural waste containing pentose sugars (such as corn cobs, bagasse, and olive pomace) with dilute acid to obtain xylose hydrolysate, which is then reduced to xylitol by microorganisms. The use of microbial fermentation of hemicellulose hydrolysate to produce xylitol has the advantages of mild reaction conditions, simple operation, environmental friendliness, low relative pollution, and reliable product quality, making it a potential low-cost alternative method for obtaining this polyol.

The production process of xylitol is relatively long, but several key processes must be grasped to ensure the quality of xylitol products and the smooth progress of production. This is known as the collaborative process. Once several key processes are completed, the key points of xylitol production are grasped.

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