Objective

2

To study on the correlation between the apparent color， near-infrared spectroscopy and dynamic changes of index constituent content of samples during the processing of steamed Notoginseng Radix et Rhizoma， and to provide reference for the processing process optimization and quality control of this decoction piece.

Method

2

Samples were dried and crushed by setting three steaming temperature gradients of 100-105， 114-118， 130-136 ℃， and sampled at steaming times of 1， 2， 4， 8， 12， 24 h， respectively. The effects of different steaming temperatures and times on the color and absorption of steamed Notoginseng Radix et Rhizoma at different infrared wavelengths were observed， and principal component analysis and cluster analysis were performed on the obtained data by R 4.1.0 and SPSS 21.0 software to observe the changes in color and infrared absorption characteristics of samples. High performance liquid chromatography （HPLC） was employed to determine the content changes of notoginsenoside R

1

， ginsenoside Rg

1

， ginsenoside Rb

1

， ginsenoside Re， 20（

S

）-ginsenoside Rg

3

and 20（

R

）-ginsenoside Rg

3

before and after steaming of Notoginseng Radix et Rhizoma， mobile phase was acetonitrile （A）-water （B） for gradient elution （0-30 min， 19%A； 30-60 min， 19%-44%A； 60-78 min， 44%-74%A； 78-80 min， 74%-100%A； 80-86 min， 100%A； 86-87 min， 100%-19%A； 87-95 min， 19%A） with the detection wavelength of 203 nm.

Result

2

During the steaming process of Notoginseng Radix et Rhizoma， with the increase of steaming temperature and time， the

b

*

（yellow-blue value），

L

*

（brightness）， △

E

*

（comprehensive color difference value） of sample powder showed a decreasing trend， while the

a

*

（red-green value） showed an increasing trend， and the color gradually deepened from gray to brown and dark black. There was no significant difference in the infrared absorption between raw and steamed Notoginseng Radix et Rhizoma sample powder in the low and medium wavelength bands， but significant difference in the infrared absorption of high band， especially in the band of 9 600-10 000 cm

-1

. HPLC showed that the contents of the original components （notoginsenoside R

1

， ginsenoside Rg

1

， Re and Rb

1

） decreased and 20（

S

）-ginsenoside Rg

3

and 20（

R

）-ginsenoside Rg

3

were newly produced after steaming of Notoginseng Radix et Rhizoma. The content proportion of these six index components reached the best when the steaming temperature at 130-136 ℃ and the steaming time of 1 h.

Conclusion

2

The color and infrared absorption of samples are affected by the dynamic changes of chemical composition during the steaming process， and the composition change is the result of the joint influence of steaming temperature and time. In this paper， through multi-dimensional analysis of the apparent color indexes， the change pattern of near-infrared absorption characteristics and the index components of the samples， the different process parameters of steamed Notoginseng Radix et Rhizoma were evaluated holistically， and the quality transfer pattern of its processing process was initially revealed， which can provide scientific basis for processing optimization and quality evaluation of steamed Notoginseng Radix et Rhizoma.