杜仲不同部位粗胶的提取方法

The extraction technology of gutta percha from different parts of Eucommia ulmoides Oliv.

【目的】杜仲胶是优质天然橡胶,有望替代传统的三叶橡胶,而杜仲的树叶、树皮、果实等不同部位均可提取杜仲胶。探究杜仲不同部位杜仲胶的最佳提取方法,为杜仲橡胶的广泛应用奠定基础。【方法】以杜仲树叶、树皮、果壳为试材,分别采用机械法、碱浸法和综合法提取杜仲粗胶。【结果】以机械法提取,杜仲树叶粗胶的提取率为15.00%,其树皮粗胶的提取率为13.35%,其果壳粗胶的提取率最高(24.99%);经20%的NaOH溶液碱浸后杜仲树叶的提胶率最高,经5%的NaOH溶液碱浸后杜仲树叶的提胶率最低;经10%的NaOH溶液碱浸后杜仲树皮的提胶率最高,经5%的NaOH溶液碱浸后杜仲树皮的提胶率最低;经25%的NaOH溶液碱浸后杜仲果壳的提胶率最高,经10%的NaOH溶液碱浸后杜仲果壳的提胶率最低。经不同浓度的NaOH溶液碱浸后,杜仲果壳的提胶率>树皮的提胶率>树叶的提胶率;经过浓度分别为5%和20%的NaOH溶液碱浸后杜仲树叶的提胶率存在显著差异(P<0.05),而经过浓度分别为5%和20%的NaOH溶液碱浸后杜仲树皮和果壳的提胶率均无显著差异。以综合法处理后,杜仲树叶的提胶率为0.25%,其树皮的提胶率为1.43%,其果壳的提胶率为2.02%;杜仲果壳的提胶率>树皮的提胶率>树叶的提胶率。3种提胶方法中,以机械法所提粗胶的外观品质最差,胶中含较多的残渣和杂质;以综合法所提杜仲树叶粗胶有光泽,杜仲树皮和果壳粗胶均具色白、细腻、无杂质等特点。【结论】杜仲果壳的提胶率高,以综合法提胶具有成本低、胶的杂质少等优点。建议在生产中以综合法提取杜仲果壳粗胶。

【Objective】The gutta percha is an excellent natural rubber extracted from leaf,bark and fruit of Eucommia ulmoides Oliv.,which has potential to replace traditional Hevea brasiliensis.The purpose of this study is to explore the best technology of Eucommia rubber extracted from different parts of Eucommia,and lay the foundation for the extensive application of Eucommia rubber.【Method】The leaves,barks and fruit shells of E.ulmoides Oliv.were used as research materials,and the mechanical method,alkali leaching method and comprehensive method were used to extract gutta percha.【Result】The extraction ratio of crude gum from E.ulmoides leaves was 15.00%,and the extracted ratio from bark was 13.35%,and the extraction ratio from fruit shell was the highest which was 24.99%.The extracted ratio of gum from the leaves leached by 20%NaOH solution was the highest,and that by 5%NaOH solution was the lowest;the extraction ratio of gum from the bark leached by 10%NaOH solution was the highest,and that by 5%NaOH solution was the lowest;the extraction ratio of gum from the fruit shell leached by 25%NaOH solution was the highest,and that by 10%NaOH solution was the lowest.The materials for extracting gum followed the decreasing order of extracted ratio as fruit shell,bark and leaves leached by different concentration alkaline solutions;the gum contents of E.ulmoides Oliv.leaves soaked in 5%NaOH and 20%NaOH solution were significantly different(P<0.05),and there was no significant difference between bark and shell;the gum content of E.ulmoides Oliv.leaves extracted by comprehensive method was 0.25%,and that of bark and fruit shell was 1.43%and 2.02%respectively;the gum content of E.ulmoides Oliv.shell>the gum content of bark>the gum content of leaves.The mechanical method was the worst as the poor appearance of the gum with more residual and impurities.The gum extracted from leaves by the comprehensive method had the characteristics of luster,white,fine and no impurities.【Conclusion】The extraction ration of gum from fruit shell is higher.The comprehensive method has the advantages of low cost and less impurities,which is suggested in the producing crude gum of Eucommia ulmoides Oliv..