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In recent years, functional oligosaccharides because of its unique physiological functions, in particular, can promote the proliferation of intestinal bifidobacteria, good for intestinal health attention has been paid. XOS, also known as wood oligosaccharides, belongs to the kind of functional oligosaccharide, D-xylose, from 2 to 7 of a combination of β-1, 4 - glycosidic bond of wood, mainly in the xylan-rich plant resources, such as wood chips, corn cob, cottonseed hulls, rice hulls, and rapeseed shell as raw material, by endo-xylanase hydrolysis, separation, purification system. The XOS is extremely difficult to be digested and absorbed, intestinal survival rate, with excellent bifidobacteria, its utilization is higher than other functional oligosaccharide. Corn is one of the three major food crops in China, the annual production is extremely impressive, in addition to a small amount of initial processing of the vast majority of farm fuel is burned has not been fully utilized, it would be a waste of resources and pollution of the environment, therefore, to carry out corncob as raw materials, production XOS research is very necessary. This paper discusses the preparation method of the XOS: activated carbon refining system XOS corncob as raw material to extract xylan, secreted by Aspergillus niger xylanase hydrolysis of xylan. The main component of the detection XOS capillary electrophoresis. Xylan Production: corn cob pretreated by adding NaOH and distilled water (corn cob powder solid-liquid ratio of 1:10), so that the base concentration was 10%, 100 ° C water bath for 2 h, with concentrated hydrochloric acid and to neutral. Precipitate dried to obtain a crude xylanase yield was 22.7% (g crude xylanase / g corn cob). Determine Aspergillus niger xylanase optimal conditions: mixed solid medium the corncob powder with carbon source C, added to the amount of the ratio of 6:4, with 1% nitrogen source N 1 solid The liquid ratio 1:2,28 ° C cultured 84h. After extraction with 0.05mol / L acetate buffer (pH 4.6) solid medium 2h (solid-liquid ratio 1:5), filtered, and the supernatant was added to the saturation degree of 70% (the NH 4 ) 2 SO 4 salt Analysis 1.5h, the precipitate was freeze-dried to obtain a crude enzyme. Desalination measured part of the nature of the xylanase: optimum reaction temperature is 45 ℃, the optimum pH value of 3.6. The enzyme is relatively stable within a range of pH3.0 to 11.0, 50 ° C or less, good thermal stability, general metal cation has little effect on the enzyme, suitable for the Xylo industrialized production. 50 ml of buffer solution (pH3.6) was added 0.01% xylanase enzymatic hydrolysis of xylan xylanase conditions: shaking speed of 200r/min, temperature of 45 ° C. The conditions under 2g crude wood glycans 5h. XOS concentration of 4.02mg/ml, XOS 44.2% of the total sugar concentration. Using activated carbon column was separated and purified by XOS. Shen off with distilled water and 15% ethanol can be purified XOS, the recovery rate was 78.1%, 82.6% purity. Pre-column derivatization capillary electrophoresis method for the determination of the main components of XOS. Uncoated silica capillary, 75 mmol / L borax (pH 10.5) running buffer, detection wavelength 214 nm, separation voltage 10kV XOS main component of alpha-naphthylamine derivatives Separation and Determination. The results show that this method is good reproducibility, the xylobiose migration time and peak area relative standard deviation of less than 0.5% and 2.0%, respectively. Xylobiose concentration within the range of 0.0001 ~ 1.000mg/ml between the peak area of ??the content of the good
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