Modern drying processing method for Angelicae Sinensis Radix based on multi-bioactive constituents / 中国中药杂志

ABSTRACT

To provide a scientific basis for the selection and optimization of the modern drying processing method for Angelicae Sinensis Radix (ASR). Three phenolic acids (esters), 6 phthalides were determined by using UPLC-PDA while polysaccharides were determined by UV-Vis spectrophotometry. Then the effects of drying methods on the inner qualities of ASR were evaluated through principle components analysis (PCA) combined with the appearance properties after drying. Results showed that the contents of chlorogenic acid and ferulic acid in samples obtained with controlled temperature and humidity drying (CTHD), medium and shortwave infrared drying (MSID) and microwave vacuum drying (MVD) methods were significantly higher than those with primary drying processing(PDP) method and the fresh samples. Multivariate statistical analysis showed that samples processed with CTHD had more similar general chemical properties with those processed with PDP, suggesting that CTHD was appropriate for the modern primary drying processing of ASR. With samples processed with traditional PDP method as reference, the CTHD method was further optimized in the processing parameters for ASR by orthogonal experiment design. Considering the consumption of drying power and time and other parameters, the modern drying parameters for the primary drying processing of ASR were finally optimized as follows controlled temperature and humidity drying at 40-45 ℃, relative humidity below 25% and target moisture content about 50% in the first stage of drying process, tempering for 12-24 h, and then drying under the conditions of temperature at 50-60 ℃, relative humidity below 20% and fan frequency at 30-40 Hz in the second stage. The study provided the scientific evidence for the selection of appropriate drying method and suitable parameters for the modern primary drying processing of ASR, as well as the beneficial exploration and practice on the formation of technical standard of primary drying processing for roots and rhizomes types herbal medicines.