天冬走油的相关因素分析及限量标准的制定

Analysis of factors related to oil-spilling and establishment of limit standards of Asparagi Radix

收集了市场上的天冬样品,采用人眼观察并记录色泽,判断是否变质。采用烘干法测定水分。采用色差仪测定色度值并计算色差值,随着天冬色泽的加深,L*下降,a*和ΔE*升高,说明色差仪测定的结果可以代替人眼观察的色泽结果。建立了高效液相色谱法(HPLC)并测定5-羟甲基糠醛(5-HMF)的含量,结果显示,色泽为黄白色或淡黄棕色的一些样品中5-HMF为0.002 255～0.049 14 mg·g-1,色泽为棕褐色的一些样品中5-HMF明显升高到0.080 80～0.105 1 mg·g-1,走油并呈褐色的样品中5-HMF高达1.033 mg·g-1,说明随着天冬色泽的加深,5-HMF的含量显著升高。采用双变量相关性分析和聚类分析进行了多种因素相关性的剖析,结果认为,5-HMF的含量与L*呈极显著负相关(P<0.01),与a*和ΔE*呈极显著正相关(P<0.01),走油变质的样品与合格的样品各自聚为一类。建议天冬中5-HMF的含量不得高于0.02%,或L*不得低于50。该文首次系统地对天冬进行了与走油变色有关的多因素的分析并制定了相应的限量标准。

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.