OBJECTIVE

2

To investigate the correlation of component content with colorimetric values during the roasting process of

Ziziphus jujuba

， and to provide criteria for discriminating the roasting degree of

Z. jujuba

.

METHODS

2

Samples were prepared by dry stir-frying for different roasting times. The eight main components in raw

Z. jujuba

and the samples stir-fried for different roasting times-namely adenosine， magnoflorine， jujuboside A， spinosin， 6-feruloylspinosin， betulinic acid， oleic acid， and linoleic acid-were quantitativel

y analyzed using ultra-performance liquid chromatography. The chromaticity values were determined using a UV spectrophotometer. The correlation and differences between the chromaticity values of

Z. jujuba

at different roasting times and their components content were analyzed by Pearson correlation analysis， linear regression analysis， principal component analysis （PCA） ， cluster heatmap analysis （CHA）， and partial least squares discriminant analysis （PLS-DA） to clarify the processing endpoint.

RESULTS

2

As the roasting time increased， the contents of linoleic acid and oleic acid decreased， while the contents of other components exhibited an increasing trend. Concurrently， the colorimetric value L* and E*ab were observed to decline， whereas the a* value demonstrated a gradual increase. Pearson correlation analysis revealed that L* and E*ab exhibited a significant negative correlation with the contents of adenosine， spinosin， 6-feruloylspinosin， jujuboside A， betulinic acid and magnoflorine （

P

＜0.05）. The results of linear regression analysis indicate that the content of six components

including adenosine， in the medicinal material can be preliminarily predicted by analyzing the colorimetric values of

Z. jujuba

powder. PCA and CHA successfully classified raw and stir-fried samples. The PLS-DA results indicated that L*， E*ab， a*， linoleic acid content， and oleic acid content were the main parameters that differentiated the color and quality of

Z. jujuba

at different roasting times. After frying for 9 to 10 minutes， the colorimetric values L* and E*ab decreased to their minimum values and stabilized， while a* remained consistently high with little variation；simultaneously， the concentrations of the six major components， excluding linoleic acid and oleic acid， reached their peak levels.

CONCLUSIONS

2

A significant correlation between the colorimetric values of

Z. jujuba

and the

contents of six components， including adenosine， is confirmed. The optimal roasting time range is determined to be 9-10 minutes. Furthermore， the colorimetric value-component content correlation analysis method established in this study proved to be practical and applicable for discriminating the roasting degree of

Z. jujuba

.