Research On Extraction, Purification And Application Of Stachyose From Grass Silkwor

Stachyose is a common reducing functional oligosaccharide.Compared with sucrose,it has lower sweetness and lower energy value than other sugars.It is the first choice for developing functional health food in some developed countries at this stage.thing.Stachyose has a therapeutic effect on cerebrovascular diseases and can enhance the body’s immunity and resistance.The plant with the highest content of stachyose is Lithocarpus gracilis.In this thesis,the dry powder of Lithodon chinensis was used as raw material,and stachyose was extracted by microwave-assisted method.The protein was removed by TCA method,AB-8 resin was decolorized,and alcohol precipitation was carried out by Sephadex G15 dextran.High-purity stachyose was obtained by purification by glycogel column chromatography.The microwave-assisted method was used to extract stachyose from Lithops praecox,and the influence of the four main influencing factors of microwave extraction temperature,power,time and solid-liquid ratio on the extraction rate of stachyose was explored.On this basis,the stachyose extraction process was optimized by using the response surface.The experimental results showed that the optimal extraction conditions were when the microwave power was 400 W,the extraction time was 5.6 min,the extraction temperature was 60 ℃,and the ratio of solid to liquid was 1:25(g/m L).The extraction rate was 41.18%.The TCA method was used to remove the protein in the crude stachyose extract.The effects of three factors of shaking time,TCA addition ratio,and standing time on the protein removal rate were discussed.The response surface was used to optimize the experimental conditions.The final experimental result showed that the shaking time was 16 min.,TCA adding ratio 1:3(m L/m L),standing time 41 min,the maximum clearance rate of protein was 82.55%.AB-8 macroporous adsorption resin removes pigment and residual protein,the best removal rate of protein reaches 59.76%,and the retention rate of stachyose reaches 85.35%.The best decolorization rate reached 87.48%.Detected by HPLC,the concentration of stachyose was 87.04%.Taking advantage of the insolubility of stachyose in alcohol,the stachyose was precipitated with methanol,ethanol and propanol.Finally,ethanol was used as the precipitating agent.The amount of ethanol added was 85%.The yield was 92.76%.The stachyose was purified by Sephadex G15 dextran gel,and the eluted samples containing stachyose were integrated,and white stachyose powder was obtained by freeze-drying,and the samples were subjected to high performance liquid phase detection.,the final sample purity can reach 90.1%To study whether stachyose has a proliferation effect on Bifidobacterium adolescentis,PI=0.57(>0.5),which proves that it has a good proliferation effect on Bifidobacterium adolescentis.