生地黄和熟地黄中5-羟甲基糠醛的含量与色泽的相关性研究

Correlation between 5-hydroxymethylfurfural content and color of Rehmanniae Radix and Rehmanniae Radix Praeparata

本研究探讨了生地黄和熟地黄中5-羟甲基糠醛(5-HMF)含量与其色泽的相关性。自然光下人眼观察色泽;色差仪测定色度值和色差值;烘干法测定水分;高效液相色谱法测定5-HMF的含量;双变量相关性分析方法探讨色泽数据与5-HMF含量的相关性。结果显示生地黄呈棕褐或深褐色,熟地黄呈黑色。熟地黄色泽的加深体现在色度值的变化上,表现为L^*、a^*和b^*值的显著降低。各地黄样品中的水分含量均符合药典规定。5-HMF的含量在生地黄和熟地黄中分别为0.9711–25.71μg/g和213.4–4010μg/g,平均含量分别为8.059μg/g和1433μg/g。熟地黄中5-HMF的含量显著高于生地黄。生、熟地黄中5-HMF的含量与L^*、a^*和b^*值具有显著相关性。熟地黄的色泽较生地黄深。5-HMF的含量在生地黄中低于0.02%,而熟地黄中的含量高于0.02%,可作为生、熟地黄判断的标志性成分。

In the present study,we explored the correlation between 5-hydroxymethylfurfural(5-HMF)and color of Rehmanniae Radix(RR)and Rehmanniae Radix Praeparata(RRP).The color was observed by human eyes under sunlight.The chromatic value and color difference were detected by a colorimeter.The water content was determined by an oven-drying method.The 5-HMF content was determined by an HPLC method.The correlation between the 5-HMF content and the color was analyzed by bivariate correlation analysis.The results showed that the color was greyish-brown and dark brown for RR,and it was black for RRP.The deepening color of RRP was reflected in the decrease of L^*,a^*and b^*values.The water content was in accord with the requirement of Chinese Pharmacopoeia.The 5-HMF contents of RR and RRP were 0.9711–25.71μg/g and 213.4–4010μg/g,respectively.The average 5-HMF contents of RR and RRP were 8.059μg/g and 1433μg/g,respectively.The 5-HMF content in RRP was higher than that in RR.The correlations between 5-HMF content and L^*,a^*and b^*values were significant.The color of RRP was deeper than that of RR.The 5-HMF content of RRP was higher than 0.02%,while it was less than 0.02%of RR,which could be used as a marker component for judging RR and RRP.