Study on the preparation and the effect of pH of soy protein isolate-phospholipid complex emulsion system

The soybean as raw material,alkaline extraction and acid precipitation were employed to produce soy protein isolate.The composite emulsion system was prepared with the soy protein isolate,soybean phosphatide and sunflower oil by the action of homogeneous machine.By single factor test,the emulsion preparation parameters were determined as soy protein isolate:phospholipid(w/w)=10∶1,aqueous phase:oil phase(v/v)= 3∶1,soy protein isolate content was 10mg/mL,homogenization time was 30s,the speed of homogenization was 20000r/min.Different pH buffers handling complex emulsion system were selected for emulsifying activity,emulsion stability,particle size analysis and microscopy,the soy protein isolate-phospholipid complex emulsion system was stability at pH≥7.