Eupolyphaga sinensis Walker activity polypeptide soy and preparation method thereof

The invention relates to a preparation method of a Eupolyphaga sinensis Walker activity polypeptide soy. The preparation method is characterized in that the preparation method comprises the following steps: 1, selecting Eupolyphaga sinensis Walker with the protein content of greater than 60% (by dry weight); 2, roasting and crushing it; 3, adding distilled water to it according to a material/water ratio of 1:5-1:50 to dissolve it, adjusting the pH value of the obtained solution to 8.2 by a 2.5mol/L Na2CO3 solution, rapidly adding 50-1000U of an Arazyme protease, well shaking, and carrying out enzymatic hydrolysis for 1-6h in a constant temperature water bath oscillator under conditions that the temperature is 37DEG C and the rotation speed is 150r/min; and 4, carrying out enzyme inactivation on the obtained enzymatic hydrolysate, adding the enzymatic hydrolysate to a low-salt solid soy (prepared according to a BNJL-016-2003 process) in the early fermentation stage, the middle fermentation stage and the late fermentation stage, and fermenting (according to the BNJL-016-2003 process) to obtain the novel insect activity polypeptide soy with the polypeptide content of greater than 100mg /ml and the antioxidation activity (represented by the DPPH free radical clearance) of not lower than 65%. The preparation method of the soy of the invention, which treats soybean meal, wheat bran and the like as main materials and a high protein insect Eupolyphaga sinensis Walker as an auxiliary material, adopts the efficient proteolytic enzyme Arazyme (the Arazyme is a high-activity metal proteolytic enzyme secreted by a symbiotic microbe (HY-3) in the alimentary canal of Nephila Clavata) and combines a traditional soy fermentation technology with an enzyme technology, allows the Eupolyphaga sinensis Walker polypeptide soy with the antioxidation activity to be prepared.