Optimization of Preparation Technology of Microcapsules Containing Sulforaphane in Rouge Radish

For making sulforaphane have controlled-release and the sustained-release property and improving the stability of sulforaphane extracted from rouge radish,a new method for preparation of microencapsulated sulforaphane was established. In this paper,hsian-tsao gum and modified starch were used as the wall materials. And the microcapsules containing sulforaphane in rouge radish were prepared by emulsification-gel method. Based on single-factor experiments,keeping the value of the ratio between wall material and core material on 5:1,the value of content of emulsifier on 0.6%,preparation technology of microcapsules was optimized by response surface experiments. The embedding rate of sulforaphane was used as the response value,and pH,ratio of wall material,emulsification time,and stirring speed were used as the response factors. The best process conditions were:the pH was 5,the ratio of wall material was 4:1(the ratio between hsian-tsao gum and modified starch),the emulsification time was 33 min,and the stirring speed was 310 r/min. The embedding rate of the microcapsules was up to 70.63%±0.49%,and the average value of particle size of the microcapsules was(20±5) μm in these process conditions. It was found that the surface of the microcapsules was smooth and spheronization of the microcapsules was considerable by the scanning electron microscope(SEM). The sulforaphane microcapsules had a certain sustained-release property in artificial intestinal juice.