铁皮石斛采后加工及提取方法对多糖的影响

Effects of post-harvest processing and extraction methods on polysaccharides content of Dendrobium officinale

目的:揭示采后加工及提取方法对铁皮石斛多糖的影响。方法:采用直接烘干、烫后烘干、边搓边烘、烫后边搓边烘4种方法,分别在不同温度下烘干后测定药材中多糖含量;以药材粉碎与否、料液比、提取时间、提取次数为考察因素,采用L9(34)正交试验研究铁皮枫斗多糖的水煮溶出量。结果:不同采后加工方法得到的铁皮石斛药材多糖质量分数为26.59%～32.70%,边搓边烘100℃和80℃处理的铁皮石斛药材多糖含量最高;粉碎程度是影响铁皮枫斗多糖快速提取率的关键因素,直接投料水煮的方法提取率极低(仅为10.28%～38.00%)。结论:80℃边搓边烘的铁皮枫斗传统加工工艺可加速药材的干燥,且保留了较多多糖成分;而传统的铁皮枫斗直接投料法"宽汤久煮"也未必能充分提取药材中的多糖,建议临床及保健食用时选用粉碎后水煮。

Objective： To reveal the quality variation of polysaceharide in Dendrobium officinale by post-harvest processing and extraction methods, and provide a basis tot post-harvest processing and clinieat and hygienical applications of Tiepifengdou（ Dendrobii Officinalis Caulis）. Method： The content of polysaccharides were studied by 4 post-harvest processing methods, i. e. drying by drying closet, drying after scalding hy boiling water, drying while twisting, and drying while twisting after scalding by boiling water. And a series of temperatures were set in each processing procedure, An orthogonal test L9 （34 ） with crushed degrees, solid-liquid ratio, extrac- tinn time anti extraction times as factors were designed to analyze the dissolution rate of polysaceharides in Tiepifengdou processed by drying while twisting at 80 ℃. Result： The content of polysaccharides was ranged from 26. 59% to 32.70% in different samples processed hy different proe.essing methods, among which drying while twisting at 80 ℃ and 100 ℃ respectively were the best. Crushed degree was the most important influence on the dissolution rate of polysaccharides. The dissolution rate of polysaccharides was extremely low when the sample was boiled directly without crushing and sieving. Conclusion： Drying while twisting at 80 ℃ was the best postharvest processing method, which can help to dry the fresh herbs and improve the accumulation of polysaeeharides. Boiling the uncrushed Tiepifengdou for a long time as traditional method could not fully extract polysaccharides, while boiling the crushed Tiepifengdou can efficiently extract polysaceharides.