金钗石斛不同采收时间质量变化研究

Study on the Quality Changes of Dendrobium nobile at Different Harvesting Times

研究金钗石斛不同采收时间质量变化,为其适宜采收期的确定提供依据。按照2015版《中国药典》(一部和四部)测定不同时间采收的金钗石斛中的水分、浸出物、总灰分和石斛碱含量,利用比色法、苯酚硫酸法分别测定黄酮和多糖含量,采用主成分分析法分析不同时间采收的金钗石斛的质量变化并进行综合评价。两个采样点的金钗石斛水分、总灰分、浸出物和石斛碱含量均在相同时间达到最大值,多糖和黄酮含量达到最大值的时间不一致;两个采样点金钗石斛中6个检测指标在12个月均存在显著差异;两个不同采样点金钗石斛水分含量的变异系数最小,分别为5.20%和5.73%,多糖含量的变异系数最大分别为42.35%和34.78%;主成分分析法综合评定得出两个采样点金钗石斛适宜采收期分别为8月至12月和9月至翌年1月,两个采样点最佳采收期为11月。贵州赤水金钗石斛最佳采收期为11月。

The objective of this study is to investigate the quality changes of Dendrobium nobile Lindl at different harvesting times and thus to provide a basis for the determination of suitable harvest period. The contents of moisture, leachate, total ash and dendrobium of Dendrobium nobile collected at different times were determined according to the method in the 2015 edition of the Chinese Pharmacopoeia (Part 1 and 4). The contents of flavonoids and polysaccharides were determined by colorimetric method and phenol sulfuric acid method. Principal Component analysis was used to examine the quality changes of Dendrobium nobile collected at different times and to conduct comprehensive evaluation. The results indicated that the contents of moisture, total ash, leachate and dendrobium in the two samples at the two sampling points reached the maximum value at the same time, while the content of the polysaccharide and that of flavonoid reached the maximum value at different times. There were significant differences in the six indicators at the two sampling points of Dendrobium nobile in 12 months. The coefficient of variation of moisture content of Dendrobium nobile at the two different sampling points was the smallest, being 5.20 % and 5.73 %, respectively, and the coefficient of variation of polysaccharide content was 42.35 % and 34.78 %, respectively. Comprehensive evaluation by principal component analysis method indicated that the suitable harvest period of the two sampling points was from August to December and September to January, respectively, and that the best harvest period of the two sampling points was November. It is concluded that the best harvest period for Dendrobium nobile in Chishui County, Guizhou Province, is November.