Abstract:

Ultrasound pretreatment was applied to the subtilisin-catalyzed hydrolysis of Pinctada martensii muscle. The effects of four ultrasound treatment parameters such as working mode. Power, temperature and treatment time on degree of hydrolysis (DH) of Pinctada martensii muscle were investigated by single-factor method. Subsequently, response surface methodology (RSM) based on a three-level, three-variable Box-Behnken experimental design was employed to evaluate the interactive effects of three crucial variables including power, temperature and treatment time. A mathematical model for DH as a function of the three variables was established. The optimum ultrasound treatment parameters for the subtilisin-catalyzed hydrolysis of Pinctada martensii muscle were determined as follows: power 160 W and temperature 50 ℃ for an ultrasound treatment duration of 17 min. Under the conditions, the actual DH after 1 h hydrolysis was 31%, and the average peptide chain length was 3.2 bp. The relative error between the predicted and the actual values was only 0.5%.

Key words: response surface methodology, ultrasonic, Pinctada martensii muscle, ultrasonic-assisted enzymolysis