Name | D-Xylose |
Synonyms | D-Xylose α-D-Xylose D(+)-Xylose d-xylose price alpha-D-Xylopyranose (3R,4S,5R)-oxane-2,3,4,5-tetrol (2S,3R,4S,5R)-Tetrahydro-2H-pyran-2,3,4,5-tetraol |
CAS | 6763-34-4 |
EINECS | 614-092-0 |
Molecular Formula | C5H10O5 |
Molar Mass | 150.13 |
Density | 1.0348952 g/cm3 |
Melting Point | 148-153 ºC |
Boling Point | 333.2±42.0 °C(Predicted) |
pKa | 12.14(at 18℃) |
Storage Condition | Sealed in dry,Room Temperature |
Safety Description | S22 - Do not breathe dust. S24/25 - Avoid contact with skin and eyes. |
properties | xylose is a white needle-like crystal or crystalline powder, sweet, only 40% of sucrose, easily soluble in water, slightly soluble in ethanol, melting point 147~151 ℃, right optical rotation and variable optical rotation. |
Use | Five-carbon aldose, also known as DL-xylose, English name, α-D-xylose, is an important chemical raw material, in food, As a non-calorie sweetener in beverages, it is suitable for obese and diabetic patients. In industry, xylose is mainly prepared xylitol by hydrogenation. Xylose has a wide range of uses in food, medicine, chemical industry, leather, dyes and other fields. |
function | xylose is used as a base material for functional foods. It has the following main functions:(1) It is not digested and absorbed, has no energy value, and can maximize the needs of people who love desserts and worry about getting fat;(2) Activate the bifidobacteria in the human intestine and promote its growth Bifidobacteria are beneficial bacteria. The more the bacteria, the more beneficial to human health: eating xylose can improve the human body's microbial environment and increase the body's immunity;(3) It is not used by microorganisms in the oral cavity and can prevent dental caries;(4) It has part of the physiological functions of dietary fiber, which has the effects of lowering blood lipids, lowering cholesterol and preventing intestinal cancer [q;(5) Xylose and food The compatibility is very good, adding a small amount of xylose to the food can reflect a good health care effect. Xylose and calcium are taken at the same time, which can improve the body's absorption rate and retention rate of calcium, and can also prevent constipation. |
preparation | xylose is the main raw material for xylose production. xylose is mainly prepared by hydrolysis of agricultural waste with inorganic acid. From a theoretical point of view, plants containing hemicellulose can be used as raw materials for xylose production. Corn cob, bagasse, rice husk, etc. are widely used as raw materials for xylose production in my country. These raw materials have the advantages of high hemicellulose content, wide sources, large yield, easy concentration, and high xylose yield. They are ideal raw materials for production. The preparation process of xylose under a certain pressure and temperature, the inorganic dilute acid is added to the raw material rich in hemicellulose. The main component of hemicellulose is polypentose, and polypentose plus acid can be hydrolyzed into xylose mother liquor. The reaction formula is as follows: Figure 1 Preparation reaction formula of xylose At present, the preparation methods of xylose mainly include neutralization deacidification process and ion exchange deacidification process. In addition, the xylose preparation process includes electrodialysis deacidification method, crystalline xylose method and chromatography separation method. Neutralization deacidification process and ion exchange deacidification process are two sets of relatively mature production processes in China, while ion exchange deacidification process has a wider application in industry because it solves the defects of neutralization deacidification process. Neutralization method deacidification preparation of xylose process The process route of neutralization method to prepare xylose is: raw materials (I. e. agricultural fiber waste), which have undergone raw material pretreatment, hydrolysis, neutralization and decolorization, ion exchange impurity removal, concentration and crystallization, and finally separation Get xylose crystals. Among them, the raw material pretreatment removes the gum, pectin, ash, etc. in the raw material; after pretreatment, the hemicellulose with polypentose as the main composition is cracked under acid catalysis and combined with water to form sugar: The neutralization process is mainly to remove the inorganic acid in the hydrolysate: the decolorization and impurity removal process includes the use of activated carbon and ion exchange resin. This process can remove the pigment and some impurities in the xylose mother liquor: the concentration and crystallization process can obtain xylose crystals by evaporating a small amount of organic acid in the hydrolysate, and controlling the concentration and crystallization time of the concentrated xylose liquid. Preparation of Xylose by Ion Exchange Deacidification Xylose is a kind of reducing sugar with stable properties under acidic conditions and extremely unstable under alkaline conditions. When the hydrolysis solution is neutralized with lime, the local pH value is too high, which will inevitably denature some xylose and affect the quality of the finished product. At the same time, the neutralization process not only removed some sulfate ions, but also brought in some calcium ions, increasing the burden on the cation exchange column. The shortcomings of equipment scaling in the neutralization and deacidification process are solved. The process route for the preparation of xylose by ion exchange deacidification is: raw materials (I. e. agricultural fiber waste), which have been pretreated by raw materials, hydrolyzed, decolorized, ion exchange impurity removal, concentrated and crystallized, and finally separated to obtain xylose crystals. |