Study on Extracting Concentrated Milk Serum Protein by Different Methods

[Objective]The aim was to explore an economic,simple and easy-to-operate extraction technology of concentrated milk serum protein.[Method]With waste liquid of milk serum as raw material,the concentrated milk serum protein was extracted by using alcohol precipitation,alkali precipitation and alcohol+alkali precipitation and the extraction effect of different methods was compared.[Result]The factors influencing milk serum protein output for extraction using alcohol precipitation were as follows:precipitation timealcohol concn.precipitation temperature and its optimum condition was as follows:the alcohol concn.was 100%,the precipitation temperature and time were 50 ℃ and 1.5 h resp.The factors influencing milk serum protein output for extraction using alkali precipitation were as follows: precipitation timepH valueprecipitation temperature and its optimum condition was as follows:the pH value was 10,the precipitation temperature and time were 30 ℃ and 1.5 h resp.The factors influencing milk serum protein output for extraction using alcohol+alkali precipitation were as follows: precipitation timeprecipitation temperaturepH valuealcohol concn.and its optimum condition was as follows:the alcohol concn.,the precipitation time,pH value and precipitation temperature were 90%,2.0 h,7 and 20 ℃ resp.[Conclusion]The effect of extracting concentrated milk serum protein using alcohol+alkali precipitation was best.