ABSTRACT
Some samples of Asparagi Radix were collected from medical markets.Colors of Asparagi Radix were observed by human vision and recorded to judge whether samples were degenerative.Water content of Asparagi Radix was determined by a drying method.The chroma value and color difference were determined and calculated by a colorimeter.With the deepening of color,the L*value was decreased and a*and ΔE*values were increased.It showed that the results determined by colorimeter can replace the results of visual observation.An HPLC method was established and used to determine the contents of 5-hydroxymethylfurfural(5-HMF) in Asparagi Radix.The results showed the 5-HMF contents were from 0.002 255 to 0.049 14 mg·g-1 in some samples with yellowish-white or yellowish-brown color,significantly increased from 0.080 80 to 0.105 1 mg·g-1 in some samples with brown color,and up to 1.033 mg·g-1 in an oil-spilling sample with dark brown color.This result demonstrated that the 5-HMF contents were significantly increased by accompanied with the deepening of color.There were the significant negatively correlation between the 5-HMF content and the L*value(P<0.01) and positively correlation between the 5-HMF content and the a*or ΔE*value(P<0.01) by the spearman analysis.The oil-spilling and qualified samples were clustered into two alone categories by the cluster analysis.That the limited standards of the 5-HMF content is not higher than 0.02% by HPLC method and of the L*value is not less than 50 by colorimeter method were suggested for Asparagi Radix.It is firstly reported the multiple-factor analysis about oil-spilling and discoloration and the establishment of limited standard of Asparagi Radix.
