The Preparation And Functional Assessment On Glyceollins Accumulation Of Cello-oligosaccharides By Wheat Straw Hydrolyzed With β-glucanase

As a kind of oligasacchrides, functional cello-oligosaccharides has the potential to be applied infeedstuff and aquaculture, food industry, cosmetics and pharmacy industry; Glyceollins arelow-molecular-weight antiestrogen compounds that accumulate in soybeans tissues in response to stress.Previous studies have shown that glyceollins have the potential of antioxidation and anti-tumor effect.The mainly aims and methods of this paper were shown on the following aspects.(1) The mixed-acid hydrolysis was selected for the separation process, in which we were able toget mixed oligosaccharides from microcrystalline cellulose. To get pure cello-oligosaccharides withdegrees of polymerization from2to5, ethanol-water gradient elution of the product onchromatographic columns composed of charcoal was applied. The products were detected by thin-layerchromatography(TLC),high performance liquid chromatography(HPLC),fluorescence-assistedcarbohydrate electrophoresis (FACE). The results proved that yields afforded by the procedure can beused as standards.(2) The optimal condition of sodium hydroxide pretreatment for wheat straw was obtained throughanalyzing the content of cellulose and effect on cellulose hydrolysis after pretreatment. The wheat strawwas treated with four different sodium hydroxide solution (0%,1%,2%,3%). The wheat straw powderwas hydrolyzed by72%sulfuric acid after the pretreatment. With the purpose of getting the content ofpowder, HPLC was applied to detect the content of glucose. The effects of this pretreatment on theenzymatic hydrolysis were also researched by calculating the conversion rate of wheat straw powder.Under the optimal condition of1%sodium hydroxide, the contents of cellulose was44.13%, wheatstraw powder rate of20%was hydrolysed with β-glucanase within2h run time.(3) The single factor experiments for optimal conditions were temperature, pH, E/S, concentrationof wheat straw and the hydrolysis time. The optimal conditions for hydrolysis of wheat straw wereobtained through analyzing the yield of cellobiose and the conversion rateof wheat straw. The optimumconditions for wheat straw hydrolysis are as follow: reaction temperature which was at50℃, pH=5.5,E/S=0.4, concentration of wheat straw=2%, and hydrolysis time=10h. Under the optimum conditions,the cellobiose yield was148.15mg/g wheat straw and the conversion rate of wheat straw was55.57%.(4) The soybeans which have bean soaked in sterile water for5h were elicited by the product ofhydrolysed wheat straw. It proves the product of hydrolysed wheat straw a good elicitor of glyceollins.The single factor experiments for optimal conditions were time course experiment, the concentration ofthe elicitor and the moisture. The optimal conditions for the accumulation of glyceollins were as follow:four times dilution of the product of hydrolysed wheat straw (1.01%cellbiose), humidity of50%in thedark for3days. Results from the optimal conditions research indicated that maximum concentrations ofglyceollins was2.22mg/g dry weight soybeans.