Extraction Of Flammulina Velutipes Polysaccharides And Effects On Fermented Milk Quality Improvement And Hypoglycemic Function

Flammulina velutipes polysaccharide,as the main active substance of Flammulina velutipes,has become a focus of attention due to its extensive physiological activity.The addition of polysaccharides to probiotic fermented milk is a hot research topic in functional dairy products in recent years.This paper uses ultrasonic-assisted extraction to extract Flammulina velutipes polysaccharides,optimizes the extraction process based on the polysaccharide ratio,and further purifies and isolates the crude polysaccharides of Flammulina velutipes,analyzes its physical and chemical properties and structural characteristics,and adds Flammulina velutipes polysaccharides to fermented milk as health factors To study the physical and chemical properties of FVP fermented milk and the biological activity of reducing blood sugar.The experimental results are as follows:(1)Optimum extraction technology of Flammulina velutipes polysaccharides:select ultrasonic time,material-liquid ratio,and extraction temperature for single factor experiments,examine the influence of each factor on the yield of polysaccharides,and optimize the factors and levels for subsequent uniform design experiments.Response surface experiments.Based on the experimental results,the optimal extraction process conditions were finally determined:Ultrasonic power 200 W,ultrasonic time of 40 min,liquid-material ratio of 20.0 g/ mL,extraction temperature of 72 ?,and repeating the test three times.(2)Isolation and purification of Flammulina velutipes polysaccharide:The crude polysaccharide of Flammulina velutipes contains protein,pigment and small molecule impurities.In this experiment,the Sevage method was used for deproteinization,decolorization of activated carbon,and small molecule impurities were removed by dialysis.After washing and separation by DEAE celluose-52 chromatography column,three components were obtained,neutral polysaccharide FVP-1,acid polysaccharide FVP-2 and FVP-3.Structural analysis of Flammulina velutipes polysaccharides:UV full-wavelength scanning analysis shows that the three polysaccharides FVP-1,FVP-2,and FVP-3 have no absorption peaks at260 nm and 280 nm,that is,they do not contain nucleic acids and proteins.The weight average molecular weights of the three polysaccharides were 11522 Da,8575Da,and7239 Da,respectively.The FVP monosaccharide composition was determined by high performance liquid chromatography.The results showed that the three FVP polysaccharides generally contained Man,Glc Ua,Gai Ua,Glc,Gai,Xyl,Ara,Sugar Fuc several simple sugars.The analysis results of infrared spectrum data show that three kinds of purified Flammulina velutipes polysaccharides have characteristic chains of polysaccharides and characteristic absorption peaks around 1000 cm-1,which are pyranose rings.It can be inferred that the three FVP monosaccharides are pyranose Based on polysaccharides.(3)Research on Flammulina velutipes fermented milk technology:Select the fermentation dose,the amount of FVP added,the fermentation temperature,and the fermentation time to conduct a single factor experiment,examine the influence of each factor on the sensory score,and optimize the factors and levels for the subsequent uniform design experiments.Perform response surface experiments.According to the experimental results,the optimal fermentation process parameters were finally determined:the fermentation dose was0.6g,the FVP addition amount was 0.06 g,the fermentation temperature was 40 ?,and the fermentation time was 7h.By comparing the physical and chemical indexes of FVP fermented milk and blank fermented milk,it was found that within a certain concentration range,FVP can significantly improve the water holding capacity of fermented milk,reduce the acidity of dairy products,ensure the taste of fermented milk,and have a significant effect on the proliferation of lactic acid bacteria.Conducive to the storage of fermented milk quality.(4)Effect of FVP polysaccharide fermented milk on hypoglycemic function:Through measuring body weight,fasting blood glucose,glucose tolerance,organ index,serum lipid index and liver section of mice,the effect of FVP polysaccharide fermented milk on hypoglycemic function was studied.The results showed that compared with the model group,mice fed with low,medium and high doses of FVP polysaccharide fermented milk gained 6.69%,8.12%,and9.23%,respectively;their blood glucose levels decreased by 3.42%,6.01%,and 7.30%;TC,TG,LDL-C concentrations were significantly reduced,HDL-C concentrations were increased,the liver and kidney indexes of diabetic mice were reduced,and the glucose and lipid metabolism disorders of diabetic mice were alleviated to a certain extent,and the liver and kidney were protected And repairing effects,so Flammulina velutipes polysaccharide has a significant effect on reducing blood sugar.