基于电子鼻和GC-MS技术分析不同干燥方式 对香葱挥发性物质的影响

Analysis of the Effect of Different Drying Methods on the Volatile Substances of Chives Based on Electronic Nose and GC-MS Technology

为了分析不同干燥方式对脱水香葱挥发性物质的影响,采用电子鼻技术和顶空固相微萃取技术结合气相色谱-质谱联用技术将经过热风干燥、红外-热风联合干燥、冷冻干燥、红外-冷冻联合干燥制得的干制香葱样品进行挥发性物质分析。结果表明,电子鼻对不同干燥方式处理的脱水香葱在传感器W5S、W1W和W2W上具有较高的响应值。两个主成分PC1和PC2的贡献率分别为71.824%和15.356%,累计方差贡献率为87.180%(85%以上),可以区分不同干燥处理的脱水香葱的挥发性风味物质。4种不同干燥方法处理后的脱水香葱分别检测到49种(热风干燥)、50种(红外-热风干燥)、66种(冷冻干燥)和53种(红外-冷冻干燥)挥发性物质。热风干燥和红外-热风干燥可以得到风味较好的脱水香葱,由于冷冻干燥温度较低,干燥过程中化合物转化率较低,可采用红外-冷冻干燥使脱水香葱产生焦香气味。因此,联合干燥方法后的脱水香葱具有更浓郁的风味。

In order to analyze the effects of different drying methods on the volatile substances of dehydrated chives,electronic nose technology and headspace solid-phase microextraction combined with gas chromatography-mass spectrometry(GC-MS)are used to analyze the volatile substances of dried chive samples prepared by hot air drying,infrared-hot air combined with drying,freeze drying and infrared-freeze combined with drying.The results show that electronic nose has a high response value on the sensors W5S,W1W and W2W for the dehydrated chives treated by different drying methods.The contribution rates of two principal components PC1 and PC2 are 71.824%and 15.356%respectively.The accumulative variance contribution rate is 87.180%(more than 85%),which could distinguish the volatile flavor substances of dehydrated chives under different drying treatments.49(hot air drying),50(infrared-hot air drying),66(freeze drying),53(infrared-freeze drying)kinds of volatile substances are detected in the dehydrated chives treated by four different drying methods respectively.Dehydrated chives with better flavor can be obtained by hot air drying and infrared-hot air drying.As the freeze-drying temperature is low and the conversion rate of chemical compounds is low in the drying process,infrared-freeze drying can be used to make dehydrated chives produce a burnt flavor.Therefore,the dehydrated chives treated by the combined drying methods have a stronger flavor.