Research On Extraction And Properties Of Hypsizygus Marmoreus Protein

[Objective] The protein was extracted from Hypsizygus marmoreus,and functional properties,physicochemical properties and digestion characteristics are researched in this experiment to provide important theoretical basis for the processing of Hypsizygus marmoreus.[Methods] Protein was extracted from Hypsizygus marmoreus by using the cellulase assisted alkali extraction and acid precipitation method,and the effect of ionic strength,temperature,sucrose concentration and p H on functional properties of Hypsizygus marmoreus protein were researched;SDS-PAGE and FTIR were used to study physicochemical properties.In addition,the digestive properties and antioxidant properties of Hypsizygus marmoreus protein were researched by simulating in vitro digestion test.[Results](1)The optimum conditions of the cellulase assisted alkali extraction and acid precipitation of Hypsizygus marmoreus protein are enzyme addition amount 3%,material to liquid ratio 1:50,enzyme hydrolysis time 2 h,p H 11.8,temperature 55?,and time 1.5 h,in the condition,the extraction rate of Hypsizygus marmoreus protein is 51.62%.(2)With the ionic strength increasing,the solubility,water holding,foaming and foaming stability,emulsibility and emulsion stability of Hypsizygus marmoreus protein increase at first and then decrease.With the sucrose concentration increasing,the solubility of Hypsizygus marmoreus protein gradually decreased,and the water holding,foaming and foaming stability,emulsibility,increase at first and then decrease,and the emulsion stability decrease at first and then increase.With the temperature increasing,the solubility,water holding,oil holding capacity,foaming and foaming stability,emulsibility and emulsion stability of Hypsizygus marmoreus protein increase at first and then decrease.With p H increasing,the solubility,water holding,foaming,emulsibility and emulsion stability decrease at first and then increase,the foaming stability increase at first and then decrease.When p H reached nearly the isoelectric point ofHypsizygus marmoreus protein,the solubility,water holding,foaming,emulsibility and emulsion stability is the minimum,the foaming stability is the maximum..(3)The molecular weight of Hypsizygus marmoreus protein subuint is 61.14 k Da?34.54 k Da?23.65 k Da?20.31 k Da and 15.41 k Da.The main amino acid composition of Hypsizygus marmoreus protein are Glu acid,L-Aspartic acid,Leucine,Proline and Isoleucine.The contents of ?-helix,?-fold,?-turn and random curl are 22.61%,29.07%,25.97% and 14.07%,respectively.The total sulfhydryl contents of Hypsizygus marmoreus protein is 154.99 ?mol/g,the free sulfhydryl contents is 5.33 ?mol/g and the disulfide bond contents is 74.83 ?mol/g.(4)After simulating gastric digestion,the digestion rate of Hypsizygus marmoreus protein is 35.51%,the hydrolysis degree is 17.13%,the free amino acid content is 0.42mg/m L,the polypeptides content is1.16mg/m L,the reducing power is 0.55,the scavenging rate of DPPH·,O2-· and ·OH are 66.14%,67.36%and 69.44%,respectively.After simulating intestinal digestion,the digestion rate of Hypsizygus marmoreus protein is 87.65%,the hydrolysis degree is 20.88%,the free amino acid content is 0.93mg/m L,the polypeptides content is 0.83mg/m L,the reducing power is 0.23,the scavenging rate of DPPH·,O2-· and ·OH are 35.02%,27.17% and 37.75%,respectively.[Conclusion] Cellulase assisted alkali extraction and acid precipitation method can effectively extract Hypsizygus marmoreus protein.The ionic strength,temperature,time and sucrose concentration have certain influence on the functional characteristics.The protein has good digestibility in the gastrointestinal tract,indicating that it is a digestible quality protein.