The Research On Extracting Xylose From The Solid Distillers' Grains Of Luzhou-flavor Liquor

Solid distillers' grains is a byproduct of the wine industry, with sorghum, potatoes, and rice as its raw materials, it also contains a lot of rice husk. China's annual wine production has reached 10 million tons, along with the increase in wine production, the distillers' grains' output is bigger and bigger. It can produce about 3 tons of distillers' grains with the production of one ton liquor. Currently, the most important application of the distillers grains is being used as feed, there are also some applications such as producing glycerine, phytic acid and phytin. There is no report of using the distillers' grains to extract xylose in the industry. As an important function of sugar and chemical raw materials, xylose is widely used in food, pharmaceutical and chemical industry. Now the main method of producing xylose is using dilute sulfuric acid to hydrolyze hemicellulose of vegetable raw materials. The main raw material is corn cobs, coconut shell, bagasse, straw, rice husk and other raw materials. The hydrolyzate is treated by removing impurity, purification, concentration, crystallization, and finally come to xylose production.This experiment used Luzhou distillers' grains as the raw materials, and then hydrolyzed the distillers' grains by dilute sulfuric acid to prepare the extract. Purified the extract by neutralization, bleaching, ion exchange, concentrated and crystallization, finally obtained the xylose product.The yield based on dride distillers' grains was 9.49%.Distillers' grains pretreatment conditions were optimized.Through the single factor experiment, inspected the effect of different pretreatment time and different pretreatment temperature on removing impurities and the yield of pentose. The optimum pretreatment conditions were determined:the pretreatment time was 90 min, the pretreatment temperature was 100?. Under this condition it could remove impurities 5.01 g, such as sand, accounting for 20.04% of the raw material quality, and the pentose production was 14.2%.In this experiment, the extract preparation conditions were optimized. First, we studied the hydrolysis temperature, time, acid concentration, solid-liquid four factors affecting the pentose yield and we got the optimum concentration range of these factors. Secondly, on the basis of single factor experiment, xylose yield as the marker, with the using of orthogonal experimental, we got the optimum hydrolysis conditions. Acid hydrolysis temperature was 120?, the acid concentration was 2%, acid hydrolysis time was 3h, the solid-liquid ratio was 1:12. Under this condition, the xylose yield was 5.97g and the yield based on dride distillers' grains was 11.94%. The optimization results were stability.The extract impurity purification conditions were optimized. Using CaCO3 as the neutralizer, the best conditions were:the temperature was 80?, the pH of the end was 3.0. Using sugar activated carbon to decolorize the extracts, the best conditions were:activated carbon 3%, temperature 80 ?, time 60min. After decolorization, the extraction liquid was treated with the ion-exchange, choosing 001x7 cation exchange resins and D301 anion exchange resins for further purification from impurity.The extract was concentrated and crystallized to obtain 18.97 g crystal. The yield based on dride distillers' grains was 9.49%. It was classified as xylose by the analysis of infrared chromatography, and its purity was 98.4% determined by high performance liquid chromatographic analysis.