Abstract:

In this work, response surface methodology (RSM) was applied to optimize the conditions for preparing microbial
lysozyme microcapsule by using sodium alginate and chitosan as coating materials. First, Plackett-Burman design (PBD) was
used to evaluate the effects of seven preparation conditions on the microencapsulation efficiency of microbial lysozyme, and the
concentrations of sodium alginate, chitosan and acetic acid were identified as main affecting factors. Then the steepest ascent
method was adopted to access the optimal region of the significant factors. At last, the optimal conditions for microcapsule
preparation were obtained from the regression equation established using Box-Behnken experimental design as follows: sodium
alginate, 2.00 g/100 mL; chitosan, 0.35 g/100 mL; and acetic acid, 0.33 g/100 mL. Under these optimal conditions, the maximum
predicted microencapsulation efficiency was 94.635% and the experimentally measured value was 92.10%.

Key words: microcapsule, alginate, chitosan, response surface method, microbial lysozyme