暗紫贝母超细粉体的制备及理化性质考察

Preparation and physicochemical properties of ultra-fine powder of Fritillaria unibracteata

目的研究暗紫贝母Fritillaria unibracteata在不同制备条件下粉体形貌和粒径分布及研磨前、后的理化性质差异,为暗紫贝母超细粉体的粒径控制与应用提供实验依据。方法设计单因素实验,采用球磨法制备不同球磨时间、球料比、转速条件下的暗紫贝母超细粉体,扫描电镜观察粉体形貌,激光粒度仪测定粉体的粒径大小和分布,对比球磨前后粉体粒径大小和分布、膨胀度、总生物碱含量等性质。结果暗紫贝母超细粉体的较优制备条件为研磨时间为0.5 h,球料比为12∶1,转速为250 r/min。暗紫贝母超细粉体体积平均粒径(D[4,3])为(26.92±0.12)μm,D90为(45.15±0.18)μm。研磨后,粒径减小,粒径分布变窄,膨胀度和休止角增大,粉体的引湿性无显著变化,松密度减小,醇溶性浸出物含量和总生物碱含量有较大提高。结论适度球磨能显著降低暗紫贝母粉体尺寸,改善粒度分布,提高总生物碱含量,有利于提高生物利用度。

Objective The morphological and particle size distribution of Fritillaria unibracteata under different preparation conditions and the physicochemical property before and after grinding were studied, which provides the experimental basis for the particle size control and application of ultra-fine powder. Methods The single-factor experiment was carried out. The ultra-fine powder was prepared using ball milling method under different milling time, the weight ratio of ball to material, and rotating speed conditions. The powder morphology was observed by scanning electron microscopy. The particle size and particle size distribution of the powder was determined by laser particle size analyzer. The particle size, particle size distribution, expansion degree, total alkaloid content, and other properties of F. unibracteata powder before and after milling were compared. Results The optimum conditions for powder preparation were as follows： The grinding time was 0.5 h, the weight ratio of ball to material was 12∶1, the rotating speed was 250 r/min. The volume average particle size of ultrafine powder was（26.92 ± 0.12） μm, and D90 was（45.15 ± 0.18） μm. After grinding, the particle size decreased, the particle size distribution became narrower, the expansion degree and angle of repose increased, the hygroscopicity of powder did not change significantly, the bulk density decreased, and the alcohol-soluble extract content and total alkaloid content increased greatly. Conclusion Moderate grinding can significantly reduce the size of F.unibracteata powder, improve the particle size distribution, increase the total alkaloid content, and help to improve bioavailability.