Reaserch On Extraction And The Functional Properties Of Pleurotus Eryngii Protein

[Object]The protein content is high in Pleurotus eryngii.This study is to extract protein from Pleurotus eryngii and explore its functional characteristics.It could provide important theoretical basis for the processing of Pleurotus eryngii and its protein utilization.[Methods]Using Pleurotus eryngii as raw material,protein extracted by three different methods includingalkaline extraction and acid precipitation,alkaline extraction and acid precipitation and cellulose enzymatic hydrolysis,Salt dissolution.Then comparing the effects of factors including ionic strength,temperature,pH levels and sugar concentration on the functional properties of Pleurotus eryngii protein,including holding water and oily,foaming property,foam stability,emulsifying property and emulsify stability.[Results](1)The best extraction processes of alkaline extraction and acid precipitation method were as follows:1:55 of material to liquid ratio,reaction temperature 50 ?,pH 12,extraction time 2.5 h,and the extraction rate was 46.21%;the best process conditions of alkaline extraction and acid precipitation and cellulose enzymatic hydrolysis were as follows:1:55 of material to liquid ratio,enzymewas 2.0%,reaction time 90 min,heating temperature 40 ?,extraction rate was 59.94%;the best extraction process conditions of salt dissolved method were:salt solution concentration was 2.0 mol/L,time 155 min,solid-liquid ratio was 1:45,heating temperature 40? and extraction rate was 36.43%.(2)Holding water property,holding oil property,foaming property and emulsifying property of Pleurotus eryngii protein reduced with theionic strength increasing;The foaming stability increased firstly,then reduced,at last increased,and the emulsion stability was increased firstly and then reduced.When the concentration was 1g/L,the foaming stability and emulsion stability was the best.The effect of temperature and sugar concentration on the holding water property,holding oil property,foaming property and emulsifying property increased firstly and then reduced.The effect of the temperature on foam stability and emulsion stability increased firstly and then reduced,and the effect of sugar concentration on foam stability and emulsion stability reduced firstly and then increased.When the sugar concentration was 2 g/Land 1.5 g/L,the stability was the worst.The minimal effect of pH on the holding water property,holding oil property,foaming and emulsifying properties were at the isoelectric point(isoelectric point 3.6).Away from the isoelectric point,the property values increased,and its impact on foam stability and emulsion stability were opposed.[Conclusion]Pleurotus eryngii protein content ofcellulose alkaline extraction and acid precipitation and celluloseenzymatic hydrolysiswas higher than both of the other methods.The ionic strength,temperature,sucrose concentration and pH had some influences on the functional properties of protein,so the processing method needs to be selected as the product properties.