核桃壳木醋液的制取、成分分析及抑菌试验

Preparation, chemical constituents analysis and antimicrobial activities o pyroligneous acid of walnut shell

为了充分利用核桃壳资源,以核桃壳为原料,采用干馏的方法,分90～150℃、150～310℃、310～550℃3个温度段收集馏出液,经静置、木炭粉吸附焦油处理等过程,制得核桃壳木醋液。然后对所得木醋液的基本性质和抑菌活性进行了研究,并对抑菌活性最强的木醋液的化学成分进行了分析。结果表明:核桃壳木醋液产生的温度范围为90～550℃;各温度段所得木醋液精制后的得率随干馏温度的增加而降低,密度随温度增加而增加,pH值随温度升高呈增加趋势,有机酸含量则呈降低趋势;各温度段核桃壳木醋液对测试菌均有抑制作用,尤其是较高温度段(150～310℃、310～550℃)的抑菌效果较好。气相色谱-质谱(GC-MS)分析表明,温度段为150～310℃的木醋液中含有约43种化合物,其中主要成分为酸类、酚类、酮类、醛类和杂环化合物等。其中含量最多的是酚类化合物和有机酸,其含量占总检出成分的80.70%。初步分析其抑菌的有效成分为酚类物质。

To achieve the comprehensive utilization of walnut, pyroligneous acid was prepared by pyrolyzing walnut shell. Pyroligneous acids of walnut shell collected at different temperature ranges, i. e., 90～150℃, 150～310 ℃and 310～550℃ were obtained. Antimicrobial activities of each pyroligneous acid were tested by using different fungus or bacteria. Chemical constituents of the pyroligneous acid showing the strongest antimicrobial activities were analyzed by Gas Chromatography-Mass Spectrometry（GC-MS）. The results showed that the temperature range of preparing pyroligneous acid by using walnut shell was 90～550℃; Yields of refined pyroligneous acid decreased along with the increase of pyrolysis temperature, while the densities and pH values increased, and the contents of organic acids decreased. All the pyroligneous acids collected at different temperature ranges showed antimicrobial activities, and significant differences existed with the control. 43 compounds were found by GC-MS analysis from the pyroligneous acid collected at the temperature range of 150～310℃, mainly organic acids, phenols, ketones and aldehydes. It was suggested that phenols, accounting fur 80.70% of the total constituents detected, were the active components for antimicrobial activities.