Abstract:

Response surface analysis based on a 3-variable, 5-level quadratic orthogonal rotation combination design was employed to investigate the optimal conditions for the bi-enzymatic hydrolysis with Neutrase and Flavourzyme of duck plasma proteins for the production of small peptides. In the optimization, a mathematical model describing the degree of hydrolysis of duck plasma proteins as a function of pH and hydrolysis temperature and time was established. Variance and confidence analyses demonstrated satisfactory fitting degree of the model (Root MSE = 0.488768). The optimal values of pH and hydrolysis temperature and time were determined through data analysis using SAS software to be 7.1, 50.5 ℃ and 4.8 h. The small peptides obtained under such conditions had no unpleasant smell and exhibited a slight taste, 798.5 nm average particle size, 0.82634 m2/g s specific surface area, － 8.63 mV Zeta potential, 0.4388 g/g water absorption ability and 8.323 mL/g oil adsorption ability.

Key words: duck plasma, Neutrase, Flavourzyme, enzymolysis, response surface methodology