decoction pieces processed by different drying methods.
METHODS
2
Adobe Photoshop 2020 software was used to determine the red green degree (
a
), yellow blue degree (
b
) and brightness (
L
) values of
A. dahurica
decoction pieces processed by 3 drying methods as steamed-cut and fresh-cut-dried, and semi-fresh-cut-dried. The contents of nine coumarins such as umbelliferone in
A. dahurica
decoction pieces processed by 3 drying methods were determined by HPLC. SPSS 26.00 software and SIMCA14.0 software were used to conduct principal component analysis and partial least squares-discriminant analysis on the content of coumarin in 32 batches of
A. dahurica
decoction pieces. Gray correlation analysis was conducted on the color of the powder and the coumarins contents in
A. dahurica
decoction pieces.
RESULTS
2
The
a
,
b
and
L
were 0-2.4, 6.0-20.3 and 35.6-51.1 in 32 batches of
A. dahurica
decoction pieces. The contents of umbelliferone, byakangelicin, psoralen, xanthotoxin, bergapten, oxypeucedanin, imperatorin, phellopterin and isoimperatorin were 0.026-0.324, 0.051-0.549, 0-0.113, 0-0.398, 0.256-1.115, 1.434-6.014, 1.866-4.039, 0.742-1.455 and 0.789-2.642 mg/g, respectively. And the total content ranged 6.442-13.382 mg/g, respectively. The results of principal component analysis showed that the comprehensive scores of BZ-27-BZ-30 and BZ-32 batches of semi-fresh-cut-dried decoction pieces were in the top
order, and the internal quality of the other two kinds of decoction pieces was quite different. The results of partial least squares discriminant analysis showed that semi-fresh-cut-dried decoction pieces were clustered into one category, poor separation was observed in steamed-cut and fresh-cut-dried decoction pieces. Results of gray correlation analysis showed that the correlation coefficients of
L
and
b
with bergapten, oxypeucedanin, imperatorin, phellopterin, isoimperatorin and
b
with psoralen were all greater than 0.8,
a
had a low correlation with all components.
CONCLUSIONS
2
The appearance traits of
A. dahurica
decoction pieces have strong correlation with the contents of coumarins. The quality of the decoction pieces can be roughly judged by the color, i.e. the whiter the color of the decoction pieces, the better the quality. The quality of sample obtained by semi-fresh-cut-dried is better than steamed-cut and fresh-cut-dried decoction pieces.