Objective

2

Taking Achyranthis Bidentatae Radix（ABR） from different origins as samples， to quantitatively analyze the chemical composition and chromaticity of ABR with different processing degrees， and clarify the correlation and change law between color and composition in the processing process of ABR， so as to provide reference for the quality evaluation of processed products of ABR.

Method

2

The colorimeter is used to measure the chromaticity values of three kinds of processing degrees of ABR in different origins to show the color value change trend during the processing process， and the color parameters of wine-processed and salt-processed products of ABR with different processing degrees were analyzed by principal component analysis（PCA）， orthogonal partial least squares-discriminant analysis（OPLS-DA） and other analysis methods. The contents of eight representative components of ABR were measured by high performance liquid chromatography（HPLC）， the correlation between chromaticity and each representative component was analyzed by Pearson correlation analysis， and the applicability of the selected eight representative components was further verified by Fisher linear discriminant analysis， and the wine-processed and salt-processed products of ABR with different processing degrees were grouped according to the degree of processing， and 48 samples of wine-processed and salt-processed products with different processing degrees were used as training samples. Taking the contents of 5-hydroxymethylfurfural， polypodine B，

β

-ecdysterone， 25

R

-inokosterone， 25

S

-inokosterone， ginsenoside Ro， chikusetsusaponin Ⅳa and polysaccharides as variables， the discriminant function was established respectively， and 12 samples of wine-processed and salt-processed products of ABR with different processing degrees were back-tested to verify the discriminant function and test the reliability of the function.

Result

2

PCA and OPLS-DA results showed that ABR samples with different processing degrees were classified into clusters， and the results could significantly distinguish different processed products. During the process of wine and salt processing， the contents of 5-hydroxymethylfurfural， ginsenoside Ro

，

and chikusetsusaponin Ⅳa gradually increased with the deepening of the processing degree， while the contents of polypodine B，

β

-ecdysterone， 25

R

-inokosterone， 25

S

-inokosterone and polysaccharides showed a gradual decreasing trend， indicating these 8 components increased and decreased to different degrees in the process of wine and salt processing. The results of Pearson correlation analysis showed that the 5-hydroxymethylfurfural content of the samples with different processing degrees of wine-processed and salt-processed products were negatively correlated with the brightness value（

L

*

） and the total color difference value（

E

*

ab

）（

P

<

0.01）， and positively correlated with the red-green value（

a

*

） and the yellow-blue value（

b

*

）（

P

<

0.01）， and that the content of polypodine B and polysaccharides were positively correlated with

L

*

and

E

*

ab

（

P

<

0.01）. The discriminant functions of wine-processed and salt-processed products of ABR were established by Fisher linear discriminant analysis， and their accuracy rates in the training samples were 93.75% and 95.83%， respectively. Twelve test samples of wine-processed and salt-processed products with different processing degree were back substitution， and the correct rate was 100%.

Conclusion

2

The trend of composition and color changes of ABR with different processing degrees in different production areas is relatively consistent， and the color value can better distinguish ABR with different processing degrees， and the color of ABR is related to some representative components in the processing process， indicating that the color can provide reference for the identification of the processing degree of ABR and the prediction of component content.