海南产不同等级香草兰豆挥发性成分分析

Analysis of Aroma Components of Different Grades of Vanilla Originated form Hainan

采用电子鼻和顶空固相微萃取-气相色谱-质谱联用技术,分析海南产不同等级香草兰豆挥发性香气,采用高效液相色谱技术检测主要香气物质的含量。结果表明:不同等级香草兰豆的整体香气在电子鼻主成分分析图谱上有显著性差异;顶空固相微萃取-气相色谱-质谱技术共检测出75种挥发性香气成分,一级、二级、三级豆分别检测出67、65种和60种,相对含量最多为香草醛,分别为58.86%、56.66%、43.90%,不同等级香草兰豆的芳香族类、醛类、酮类、酸类、醇类、杂环六大类香气化合物相对含量有明显差异,芳香族类是香草兰豆中最主要香气化合物,相对含量分别为88.99%、88.35%和82.55%;高效液相色谱检测结果表明,与二级和三级豆相比,一级豆中香草醛、香草酸相对含量最高,分别为3.56%、0.21%;二级豆中对羟基苯甲醛相对含量高于一级和三级豆,为0.15%;在3个等级豆中,三级豆对羟基苯甲酸相对含量最高为0.03%。

In this paper, electronic nose（E-nose） coupled with solid-phase microextraction-gas chromatography-mass spectrometry（SPME-GC-MS） was used to analyze the aroma components of different levels of vanilla pods originated from Hainan. Besides, the contents of main aroma components were detected by high performance liquid chromatography（HPLC）. The results indicated that overall aroma of different levels of vanilla pods could be distinguished by principal component analysis（PCA） of E-Nose data. A total of 75 aroma components were identified through SPME-GC-MS, 67, 65 and 60 of which were detected in level 1, 2 and 3 of vanilla pods, respectively. The three levels of pods showed the highest vanillin content of 58.86%, 56.66% and 43.90%, respectively, compared to other aroma components. Significant differences existed in the relative contents of aromatic species, aldehydes, ketones, acids, alcohols, and heterocyclic substances from different levels of vanilla pods. Aromatic species were the most abundant aroma compounds of vanilla and their relative contents were 88.99%, 88.35% and 82.55% in level 1, 2 and 3 of vanilla pods, respectively. The HPLC results indicated that compared with the second and third levels, the contents of vanillin and vanillic acid were higher in the first level of vanilla pods with values of 3.56% and 0.21%, respectively. The content of p-hydroxy benzaldehyde（0.15%） was higher in the second level than in the first and third levels of pods. The content of p-hydroxy benzoic acid（0.03%） was the highest in the third level among the three levels of vanilla pods.