地黄叶总苷浸膏真空带式干燥工艺优化研究

Optimization for Vacuum Belt Drying Process of Rehmannia Leaves Extract

关键词:  地黄叶总苷  毛蕊花糖苷  真空带式干燥  工艺比较  多指标综合评分

Key words:  total glycosides of Rehmannia leaves  verbascoside  vacuum belt drying  process comparison  grading method for multiple- index

摘要:

目的 研究地黄叶总苷浸膏真空带式干燥的最佳工艺，并与其他干燥方法进行比较。方法 以干燥产品含水率及有效成分保留率为评价指标，对影响干燥效果的因素进行考察。在单因素实验结果的基础上，采用L₉(3⁴)正交试验法，结合方差分析与多指标综合评分结果，获得地黄叶总苷浸膏真空带式干燥的最佳工艺参数，并将其干燥效果与真空烘箱干燥、微波真空干燥进行比较。结果　地黄叶总苷浸膏真空带式干燥的最佳工艺条件为传送带速度4 cm·min^-1，浸膏进料速度25 mL·min^-1，加热系统温度75 ℃，75 ℃，该条件下地黄叶总苷浸膏干燥产物含水率为2.54%，毛蕊花糖苷保留率和地黄叶总苷保留率分别为94.54%和90.49%。结论　优选得到的地黄叶总苷浸膏真空带式干燥工艺稳定可靠。与真空烘箱干燥和微波真空干燥相比，真空带式干燥具有干燥产品含水率低、有效成分保留率高、干燥时间短和可连续生产等优点，为中药浸膏的真空带式干燥工艺设计和过程控制提供了参考。

Abstract:

OBJECTIVE To select the optimum conditions of the vacuum belt drying process of Rehmannia leaves(RL) extract and compared with other drying methods. METHODS Based on the single factor test, the process was studied by using L₉(3⁴) orthogonal test design, combined with analysis of variance and grading method for multiple-index on the parameters of the water content of dried product and active ingredient retention rate of RL extract. Then, compare the optimum process of vacuum belt drying with the vacuum oven drying and the microwave vacuum drying methods. RESULTS The optimum process determined by the grading method for multiple-index was listed as follows: the belt speed was 4 cm·min^-1, the feeding speed was 25 mL·min^-1, the drying temperature was 75 ℃, 75 ℃. In these process parameters, the water content of dried product is 2.54%, the retention rate of verbascoside and total glycosides are 94.47% and 90.70% respectively. CONCLUSION The optimum conditions of the vacuum belt drying process of RL extract is stable and reliable. Compared with the vacuum oven drying and the microwave vacuum drying methods, the vacuum belt drying technology can continuous production and the drying product of this technology has high quality with lower water content, higher active ingredient retention rate and shorter drying time. This method can provide references for the process technological design and control of natural herbs extract vacuum belt drying.