樟芝发酵液挥发性物质提取方法及成分比较

Comparison of Different Extraction Methods for the Analysis of Volatile Components of the Fermentation Broth of Taiwanofungus camphoratus

采用4种常规萃取剂以及固相微萃取对樟芝发酵液中的非极性香气成分进行萃取分析,并对不同碳、氮源获得的挥发性物质进行比较和分析。结果发现,樟芝发酵液中含有大量的呈香物质,采用不同的萃取方法,得到的香气成分种类各不相同:用乙醚、或正戊烷-乙醚(1:1,V/V)萃取,得到的醛类成分数量最多,达到9种;正戊烷-乙醚(1:1,V/V)和正戊烷-二氯甲烷(2:1,V/V)为萃取剂,检测到的香气成分达50多种,但对醛类物质的萃取效果较差;使用乙醚萃取和SPME得到的香气种类接近,在40种左右;而石油醚萃取,效果最差。综合毒性和成本等因素,选取对醛类萃取效果较好的乙醚作为萃取剂进行分析。不同的碳、氮源获得的发酵液,挥发油中香气成分种类繁多,醛类香气成分的相对含量差别很大。以葡萄糖为碳源的发酵液中,醛类百分含量最高,约21.90%;以蛋白胨为氮源的发酵液中,醛类相对含量高达41.60%。结果表明,以葡萄糖和蛋白胨为碳、氮源的培养基有助于富集樟芝发酵液醛类香气成分。

Different extraction methods were comparatively evaluated for their extraction efficiencies for volatile aroma compounds in the fermentation broth of Taiwanofungus camphoratus. Changes in the composition of volatile compounds produced from different carbon and nitrogen sources in the fermentation medium were analyzed by liquid-liquid extraction and GC-MS. Results showed that there were large variations in the types and contents of volatile compounds extracted with different methods from the fermentation broth of T. camphoratust. The aldehydes extracted using diethyl ether or n-pentane- diethyl ether （1：1, V/V） had the most diverse composition, consisting of 9 compounds. Although more than 50 compounds were extracted using n-pentane-diethyl ether （1：1, V/V） or dichloromethane-n-pentane （2：1, V/V）, aldehyde components were less. About 40 compounds were identified using ether extraction or solid phase microextraction （SPME）. The extraction efficiency of petroleum ether was the worst. From the viewpoint of toxicity and cost, ether was chosen as the best extraction solvent. The composition of volatile compounds in the fermentation broth varied with different carbon and nitrogen sources. The relative content of aldehydes was approximately 21.90% and 41.60%, with glucose as the carbon source and peptone as the nitrogen source, respectively. These results indicate that glucose and peptone are in favor of the generation of volatile aldehydes in the fermentation broth of Taiwanofungus camphoratus.