Optimization of the Process for Preparation of Lactococcus lactis NZ9000 Microcapsules by Response Surface Method

The calcium alginate microcapsules containing Lactococcus lactis NZ9000 were prepared by emulsification method. The single factor and response surface experimental design were used to optimize the microcapsule particle size uniformity. Alginate concentration, CaCl2 concentration and emulsification time were chosen for further optimization by single factor experiment, Box-Behnken method was applied to design a response surface methodology experiments. A fitting multiple regression equation was given and to describe the relationship between condition levels and response value. The model in this study can be used to predict the characteristics of microcapsules, and the predicted condition to prepare minimum microcapsule diameter CV (0.2077) was as follows: soudiu alginate concentration 1.67%, CaCl2 concentration 0.91% and emulsification time 15.44 min. To validate the model, the experiment was carried out under the optimal conditions and the value of microcapsule diameter CV attained was 0.2077. The average particle size was 62.35 mu m, and the P value was 0.735 meaning no significant difference. Through this study, the preparation conditions of the calium alginate microcapsules with Lactococcus lactis were optimized, and the results could provide a guide for further studies.