In this study, daidzein microparticles (DMP) were prepared using an improved ultrasound-assisted antisolvent precipitation method. Preliminary experiments were conducted using six single-factor experiments, and principal component analysis (PCA) was adopted to obtain the three staple elements of the ultrasonic power, solution concentration, and nozzle diameter. The response surface Box-Behnken (BBD) design was used to optimize the level of the above factors. The optimal preparation conditions of the DMP were obtained as follows: the flow rate was 4 mL/min, the concentration of the daidzein solution was 16 mg/mL, the ratio of antisolvent to solvent (liquid-to-liquid ratio) was 9, the nozzle diameter was 300 μm, the ultrasonic power was 180 W (665 W/L), and the system speed was 760 r/min. The minimum average particle size of DMP was 181 ± 2 nm. The properties of daidzein particles before and after preparation were analyzed via scanning electron microscopy, X-ray diffraction analysis, Differential scanning calorimetry and Fourier transform infrared spectroscopy, no obvious change in its chemical structure was observed, but crystallinity was reduced. Compared with daidzein powder, DMP has a higher solubility and stronger antioxidant capacity. The above results indicate that the improved method of ultrasonication combined with antisolvent can reduce the size of daidzein particles and has a great potential in practical production.

在本研究中，黄豆苷元微粒 (DMP) 是使用改进的超声辅助抗溶剂沉淀法制备的。初步实验采用6个单因素实验，采用主成分分析（PCA）得到超声功率、溶液浓度、喷嘴直径三个主要元素。响应面 Box-Behnken (BBD) 设计用于优化上述因素的水平。得到DMP的最佳制备条件为：流速为4 mL/min，黄豆苷元溶液浓度为16 mg/mL，反溶剂比（液液比）为9，喷嘴直径为300 μm，超声功率为180 W（665 W/L），系统转速为760 r/min。DMP 的最小平均粒径为 181 ± 2 nm。通过扫描电镜、X射线衍射分析、差示扫描量热法和傅里叶变换红外光谱分析制备前后黄豆苷元颗粒的性质，未观察到其化学结构发生明显变化，但结晶度降低。与黄豆苷元粉相比，DMP具有更高的溶解度和更强的抗氧化能力。以上结果表明，改进后的超声联合反溶剂法可以减小黄豆苷元颗粒的粒径，在实际生产中具有很大的潜力。其化学结构未见明显变化，但结晶度降低。与黄豆苷元粉相比，DMP具有更高的溶解度和更强的抗氧化能力。以上结果表明，改进后的超声联合抗溶剂法可以减小黄豆苷元颗粒的粒径，在实际生产中具有很大的潜力。其化学结构未见明显变化，但结晶度降低。与黄豆苷元粉相比，DMP具有更高的溶解度和更强的抗氧化能力。以上结果表明，改进后的超声联合抗溶剂法可以减小黄豆苷元颗粒的粒径，在实际生产中具有很大的潜力。