Abstract: Two proteases including Bacillus subtilis neutral protease and papain are used to hydrolyze bovine bone protein by five hydrolysis methods. The optimal dual-enzyme hydrolysis conditions of bone protein were explored for maximizing hydrolysis efficiency. The results indicated that synchronous hydrolysis of bone protein exhibited a higher hydrolysis efficiency when compared with the sequential hydrolysis by papain first and then Bacillus protease or Bacillus protease first and then papain. The optimal hydrolysis conditions were total enzyme amount of 7000 U/g at papain-neutral protease ratio of 1:1, oscillation hydrolysis time of 6 h, oscillation speed of 150 r/min, hydrolysis temperature of 51 ℃, hydrolysis pH of 7.05 and substrate concentration of 10%. Under the optimal hydrolysis conditions, the degree of hydrolysis was up to 27.54%.

Key words: bone protein, hydrolysis, Bacillus protease, papain, degree of hydrolysis