基于电子感官技术结合GC-MS分析不同干燥方式下澳洲坚果风味的差异

Analysis of Flavor Difference of Macadamia Nuts Dried with Different Methods Based on Electronic Sensory Technology Combined with GC-MS

摘要:

为科学评价不同干燥方式下澳洲坚果风味的差异，采用电子舌、电子鼻电子感官技术结合气相色谱-质谱（gas chromatography-mass spectrometry，GC-MS）对其风味品质进行分析。结果表明：不同干燥处理的果仁与新鲜果仁在鲜味、咸味、酸味和苦味上差异显著，且判别函数分析（linear discriminant analysis，LDA）前两主成分的累计贡献率为96.60%，可以完全区分不同方式干燥的澳洲坚果仁。电子鼻对不同处理的澳洲坚果仁有明显不同响应，主成分分析（principal component analysis，PCA）前两主成分的累计贡献率达到98.79%，可以很好地区分不同干燥处理的澳洲坚果果仁的挥发性风味物质，传感器W1S、W3S和W3C在主成分分析时发挥主要区分作用，GC-MS作为电子鼻的补充，共鉴定出227种挥发性成分，烷烃和醛类在种类与含量上占较大优势，四种不同处理的澳洲坚果仁的烷烃相对含量分别为26.29%、40.76%、23.64%及39.46%，醛类相对含量分别为29.01%、18.96%、26.03%及23.87%。可见，通过电子舌、电子鼻和GC-MS相结合的手段，可以较好地区分不同干燥方式下的澳洲坚果，从而为澳洲坚果的采后产地初加工提供理论参考。

Abstract:

In order to evaluate scientifically the differences in the flavor of macadamia nuts dried with different methods, electronic tongue and electronic nose sensory technologies combined with gas chromatography-mass spectrometry（GC-MS）were used to analyze their flavor quality. The results showed that there were significant differences between fresh macadamia nuts and different dried macadamia nuts in umami, salty, sour and bitter tastes, and the cumulative contribution rate of the first two principal components of linear discriminant analysis (LDA) was 96.60%, which could distinguish completely macadamia nuts dried in different ways. The responses of the electronic nose to macadamia nuts processed differently differed significantly. The cumulative contribution rate of the first two principal components in principal component analysis (PCA) reached 98.79%, which could well distinguish the volatile flavor compounds of the macadamia nuts dried by different treatments. The sensors W1S, W3S and W3C played major roles in the principal component analysis. As a supplement to the electronic nose, GC-MS identified a total of 227 volatile components, with alkanes and aldehydes being dominant in types and contents. The relative contents of alkanes in the four different treatments of macadamia nuts were 26.29%, 40.76%, 23.64% and 39.46%, respectively, and the relative contents of aldehydes were 29.01%, 18.96%, 26.03% and 23.87%, respectively. Therefore, the combination of electronic tongue, electronic nose and GC-MS can better distinguish macadamia nuts dried with different methods, thereby providing a theoretical reference for postharvest primary processing of macadamia nuts in growing regions.