Abstract:This research focused on soy sauce residue.The effects of extrusion conditions on protein solubility in soy sauce residue were studied.On the basis of single factor experiment，extrusion parameters that optimized response surface were elucidated using protein solubility as a measurable index to determine best extrusion conditions.The process parameters that obtained the highest protein solubility were as follows：104℃ extrusion temperature，34% moisture content，and 96 r/min screw speed.Under these process parameters，soluble protein in the soy sauce residue reached 55.43%，which was 31.7% higher than that of the raw material before extrusion，indicating that the extrusion method significantly affected protein solubility in the soy sauce residue.