不同干燥方法对射干药材干燥特性、外观性状和有效成分的影响

探究不同干燥方法(阴干、晒干、热风干燥)对射干药材根茎外观性状和内在结构及成分的影响规律,为筛选适宜射干产地初加工的干燥方法提供理论依据。该研究通过比较不同干燥方法下,射干水分比、干燥速率随干燥时间的动态变化规律以及对射干外观性状、折干率、密度、灰分、浸出物和6种黄酮类成分(芒果苷、射干苷、野鸢尾苷、鸢尾黄素、野鸢尾黄素、次野鸢尾黄素)含量的影响。结果表明,新鲜射干采用传统阴干干燥至水分平衡点耗时最长,约311 h,晒干干燥较阴干干燥耗时缩短了约19.3%,两者干燥曲线均较平缓,晒干样品断面颜色最接近鲜样,但内部充满大量孔洞,密度较低,结构疏松;采用热风烘干干燥(40,60,80℃)较阴干干燥能节省27%~88%的时间,大幅度缩短干燥时间,药材内部孔洞较少,密度较大,结构紧实。在折干率上,热风干燥较传统干燥方法降低约13.7%;灰分受温度影响较大,40℃及以下的干燥条件下同传统干燥差异不显著,60,80℃处理中,灰分较传统干燥降低7.73%~18.5%;传统干燥及40℃热风烘干干燥后样品中射干苷与野鸢尾苷(苷类成分)含量显著高于60,80℃热风烘干干燥,而鸢尾黄素、野鸢尾黄素和次野鸢尾黄素(苷元类成分)以60℃烘干含量最佳。故综合外观性状与药效成分含量等方面考虑,热风干燥60℃处理后的药材质地坚实,内部结构紧密,外观性状较好,致毒副性苷类成分适当减少,苷元类成分含量较高。

Effect of different drying methods on drying characteristics,appearance and active components of Belamcandae Rhizoma

In order to explore the effect of different drying methods(drying-in-the-shade,sun-drying,and hot air drying)on appearance characteristics,internal structure and composition of Belamcandae Rhizoma,so as to provide a theoretical basis for screening out suitable drying methods for primary processing.In this study,the Belamcandae Rhizoma′s dynamic changes of the moisture content ratio and drying rate with different drying time under different drying methods,as well as the effects of different drying methods on the appearance,drying rate,density,ash,extractives and the contents of six flavonoids(mangiferin,tectoridin,iridin,tectorigenin,irigenin,irisflorentin)were compared.The results showed that fresh Belamcandae Rhizoma consumed the longest time to reach the water balance point by traditional dry drying in the shade,whiche was about 311 h;that by sun drying was 19.3%,which was shorter than drying in the shade;both drying curves were smoother.The section color of the sun drying samples was the closest to that of fresh samples,but the interior is full of holes,with a low density and loose structure.Hot air drying(40,60,80℃)could save about 27%to 88%of the drying time,which was greatly shorter,with less pores,a larger density and compact structure.Compared with the traditional drying method,the drying rate of hot air drying was reduced by 13.7%.Ash was affected by temperature,the drying conditions under 40℃and below were not significantly different from those of conventional drying.The ash content decreased by 7.73%to 18.5%compared with conventional drying at 60,80℃.After conventional drying and 40℃hot air drying,the contents of tectoridin and iridin(glycosides)in the samples were significantly higher than those in 60,80℃hot air drying,while the contents of tectorigenin,irigenin and irisflorentin(aglycones)dried at 60℃were the best.Therefore,considering comprehensive appearance characteristics and content of medicinal ingredients,traditional Chinese medicinal materials after 60℃hot air drying show a solid texture,tight internal structure,good appearance,appropriate reduction of toxic parasides and higher aglycone content.