白及真空冻干法与烘干法工艺条件优化对比

Optimizing and Comparative of Vacuum Freeze-Drying and Drying Method of Bletillae Rhizoma Decoction Pieces

为考察白及饮片最佳干燥工艺,并为其他中药饮片干燥工艺的现代研究提供借鉴。采用变温电阻检测法测定白及共晶点;通过测量白及饮片在蒸制切片和生切片、厚度0.1和0.2 cm、烘干和真空冻干等8种工艺条件组合下的白及多糖含量及特性黏数,进一步测定饮片折干率,绘制折干率曲线,优选最佳因素,同时进行感官品质对比,确定出白及饮片的最佳干燥工艺。结果表明:白及饮片共晶点为-11.6℃;真空冻干法优化条件为0.2 cm生切片,-25℃预冻2 h后采用真空冻干(-45℃0.28 MPa)4 h,该饮片色泽洁白,片形平整,断面特征完好,感官品质最佳,适用于处方饮片;烘干法优化条件为0.2 cm蒸制切片,60℃恒温烘干2 h,该饮片虽然感官品质较差,但是多糖含量和特性黏数最高,适用于药厂投料。本文首次报道了白及共晶点,并确定了白及饮片两种干燥模式的最佳工艺条件,为《中国药典》白及标准的进一步完善,提供了重要的参考数据。

In order to investigate the best drying technology of bletillae rhizoma decoction pieces,and to provide reference for the modern research of drying technology of other traditional Chinese medicine decoction pieces.The polysaccharides content and intrinsic viscosity of bletillae rhizoma were determined in the combination of steaming and raw slices,thickness of 0.1 cm and 0.2 cm,drying and vacuum freeze-drying,and the drying rate of bletillae rhizoma was further determined,the curve of drying rate was drawn,the best factors were selected,and the sensory quality was compared to determine bletillae rhizoma and its slices.The results showed that the eutectic point of bletillae rhizoma decoction pieces was -11.6 ℃;the optimum conditions of vacuum freeze-drying were as follows 0.2 cm raw slices,pre-freezing at -25 ℃ for 2 hours and vacuum freeze- drying(-45 ℃= 0.28 MPa) for 4 hours.The decoction pieces were white in color,flat in shape,well-sectioned,with the best sensory quality,and suitable for prescription slices;the optimum conditions of drying method were as follows 0.2 cm steaming slices,60 ℃ constant temperature drying for 2 hours,although the decoction slices were clean and smooth in color.However,the sensory quality is poor,but the content of polysaccharide and intrinsic viscosity are the highest,which is suitable for pharmaceutical factory feeding.In this paper,the eutectic point of bletillae rhizoma was reported for the first time,and the optimum drying conditions of bletillae rhizoma decoction pieces were determined,which provided important reference data for the further improvement of bletillae rhizoma standard in Chinese Pharmacopoeia.