Studies Of Preparation Of Xylooligosaccharides From Peanut Hull

Oligosaccharide (XOS) is a kind of sugar that conducive to human health.It can bepromote of intestinal bifidobacteria proliferation, enhance immunity, anti-tumor, reduce bloodpressure, blood glucose, serum cholesterol.And has other useful features of the health.Themost important problems to be solved immediately are improving XOS yield and reducing theproduction costs. China is a big country of planting peanuts.At the same time, plenty ofpeanut shell as the agricultural products should be fully utilized, too. In this thesis, peanutshells is the raw material to prepare peanut shell xylan, and then prepare peanut shelloligosaccharide using xylanase.This progress increased the productivity.And the peanut shellstructure of the xylan was studied for further provide the basis for research and application.On the basis of single factor analysis that place peanut shells in the alkaline hydrolysis toprepare xylan, by studying four factor:the alkali concentration, extraction time, extractiontemperature and solid to liquid ratio, trial the response surface optimization, the optimumcondition of salkaline hydrolysis preparation of peanut shell xylan were: alkali concentration14.5%, temperature100℃, processing time100min, solid to liquid ratio1:12, xylanextraction rate53.12%.The maximum extraction rate was48.13%, higher than the singlefactor. Xylan preparation by the alkali extraction method, based on ultrasound to be assisted,single-factor test included the ultrasound-assisted alkaline extraction of xylan responsesurface experiment.The optimal conditions were: alkali concentration7%, the processingtime80min, solid to liquid ratio1:16, temperature80℃, ultrasonic power120W.Obtained59.04%of xylan extraction rate, the maximum extraction rate was49.13%higher than thesingle factor9.91%. After ultrasound-assisted extraction rate of xylan increased4.7%,7.5%lower alkali concentration, treatment time reduced20min, hydrolysis temperature reduced20℃, effectively reducing the alkali concentration. To prevent it too high to corrosive theequipment and improve the extraction rate.By combined three analytical tools of TLC, infrared spectroscopy and nuclear magneticresonance spectroscopy, composition and structure of a sugar chain of peanut shell xylan wasstudied, the results showed that the xylanase is a peanut shell-type β pyran-glycosidic linkageof xylose as the main chain, side chains containing arabinose, glucuronic acid and acetyl ofthe polysaccharide.It is a good kind of xylanase substrate.Preparation of oligosaccharidehydrolysis process optimization by response surface optimum processing conditions:2.99%enzyme dosage, time8.34h, pH5.1, temperature of45.7℃.The extraction rate was88.40%. The average degree of polymerization was2.56.By TLC and Sephadex-25gel,the enzymatichydrolysis of the main components was xylobiose and xylotriose, Xylobiose purifieddisaccharide was45%.Xylotriose purified disaccharide was13%.