基于电子鼻与HS-SPME/GC-MS技术的香芋南瓜果实香气物质解析

Analysis of Aroma Compounds in Xiangyu Pumpkin using Electronic Nose and Head Space-Solid phase Microextraction/Gas Chromatography-Mass Spectrometry

为了解香芋南瓜果实香气挥发性成分,以及香味主要贡献物在不同发育时期的变化特征,本研究采用电子鼻方法和顶空固相微萃取结合气相色谱-质谱联用(HS-SPME/GC-MS)技术对香芋南瓜和非香芋南瓜资源进行分析。电子鼻检测结果显示,香芋南瓜和非香芋南瓜整体风味差异明显。采用HS-SPME/GC-MS技术对香芋南瓜成熟果实挥发性成分进行鉴定,共定性挥发性物质31种。利用mass profiler professional软件鉴定香芋南瓜与2类非香芋南瓜成熟果实之间的挥发性成分差异,结果表明不同资源间挥发性成分差异显著,这一结果与电子鼻分析相吻合。并且从2组比较中获得共有差异化合物2-乙酰基-1-吡咯啉(2-AP)。最后,以香芋南瓜未授粉、授粉后25 d、授粉后55 d果实为研究对象,比较了2-AP在不同发育时期的变化趋势。2-AP在未授粉及授粉25 d的果实中含量相似,而在成熟后期果实中呈现显著下降。本研究结果将为后续香芋南瓜香气性状的研究提供参考。

To understand the volatile aroma compounds in Xiangyu pumpkin fruit, and the characteristics of the main aroma contributors at different development stages of fruit, this study used electronic nose and head space solid-phase micro-extraction（HS-SPME） combined with gas chromatography（GC）-mass spectrometry（MS） to analyze the volatile compositions in both Xiangyu pumpkin and non-Xiangyu pumpkin resources. Significant differences in aroma trait were found by electronic nose between Xiangyu pumpkin and non-Xiangyu pumpkin. A total of 31 volatile aroma compounds were identified in mature fruit of Xiangyu pumpkin using HS-SPME/GC-MS. Subsequently, GC-MS and mass profiler professional were used to analyse the differences in volatile compounds between Xiangyu pumpkin and two kinds of mature non-Xiangyu pumpkin, and the obtained results revealed significant differences in volatile compounds（which was consistent with those obtained by electronic nose analysis）. And 2-acetyl-1-pyrroline（2-AP） was the unique volatile compound in Xiangyu pumpkin as compared with the two sets of control samples（non-Xiangyu pumkins）. Finally, the changing trends of 2-AP at different fruit development stages of unpollinated fruit, fruits collected at the 25 th day and 55 th day, respectively, after pollination. And unpollinated fruit and fruit obtained at the 25 th day after pollination had a similar amount of 2-AP, while the 2-AP content deceased significantly in fruit at late maturity stag. This study has laid the foundation for future studies on aroma trait in Xiangyu pumpkin.