基于HS-SPME/GC-MS和电子感官技术的热泵干燥对烘焙咖啡豆风味品质影响研究

Effect of Heat Pump Drying on Flavor of Roasted Coffee Beans Analyzed by Headspace-solid Phase Microextraction /GC-MS and Electronic Sensing

摘要:

为了探讨热泵干燥对烘焙咖啡豆风味品质的影响，本研究以日晒干燥为对照，采用顶空固相微萃取-气相色谱质谱联用（HS-SPME/GC-MS）、电子鼻和电子舌检测技术，研究了热泵干燥不同温度下焙炒咖啡豆的挥发性风味成分、气味及滋味特性。HS-SPME/GC-MS结果表明：共检测到挥发性风味成分131种，包括10大类物质；干燥温度为40 ℃时检测数目最多，为124种，随着温度升高，挥发性风味成分数目呈下降趋势，其中呋喃类化合物和吡嗪类化合物所占百分含量最高，均达到了20%以上，酮类化合物数目最多为31种。电子鼻及电子舌数据经主成分分析（PCA）降维处理，结果表明：电子鼻和电子舌的前两个主成分累积方差贡献率分别为99.66%和84.59%，均大于80%，能够较好的提取样品中多维数据信息，并且均能够有效的区分日晒干燥及不同热泵干燥温度处理所得烘焙咖啡豆。

Abstract:

Using sun-dried samples as a reference, effects of heat pump drying on the quality of the flavor of roasted coffee beans was investigated. Volatile compounds as well as smell and taste of roasted coffee beans were analyzed at different temperature by headspace-solid phase microextraction/gas phase chromatography-mass spectrometry (HS-SPME/GC-MS), electronic nose, and electronic tongue. The HS-SPME/GC-MS results showed that 131 volatile compounds were present in the samples. The highest number of compounds was found to be 124 at 40 ℃; with increasing temperature and the number of volatile compounds decreased. It was observed that furans and pyrazines accounted for the most compounds (20%), and ketones was up to 31 kinds. Electronic nose and electronic tongue results showed that the cumulative contribution rates of the first two principal components were 99.12% and 84.59%, respectively. Both were higher than 80% and were therefore used to concentrate the multidimensional information of samples. It was found that electronic nose and electronic tongue, combined with principal component analysis, could distinguish all the roasted coffee beans samples.