电子鼻对不同种类抹茶香气成分的辨别与分析

Identification and analysis of the aroma components of different species of Matcha by electronic nose

以11种不同抹茶为材料,用电子鼻对抹茶粉和抹茶汤的香气进行辨别研究,探究不同样品量、孵化温度对电子鼻测定抹茶香气的影响。通过主成分分析、判别因子分析及面积归一化法确定电子鼻检测抹茶香气的最佳参数和香气组成及差异。结果表明,电子鼻对抹茶粉的区分辨别优于抹茶汤,在0.5 g抹茶粉,孵化温度为60 ℃时,电子鼻识别指数可达98%,重复性和辨别性最好。11种抹茶通过电子鼻定性检测到259种香气成分,其共有的香气成分有35种,主要的香气成分及其相对含量分别为芳樟醇(4.38%~9.76%)、苯甲醇(0.94%~2.45%)、乙酸庚酯(2.26%~5.79%)、大马士酮(2.32%~3.46%)、Delta-戊内酯(1.21%~3.08%)、2-壬醇(2.33%~5.35%)、香叶醇(2.35%~6.77%)、壬醛(2.59%~4.38%)、乙酸反-2-己烯酯(1.01%~3.86%)、(S)-(-)柠檬烯(1.26%~2.53%)、4-甲基壬烷(1.0%~2.33%)和月桂烯(1.03%~2.27%)。电子鼻能对不同种类抹茶香气进行较好地辨别和分析,为今后抹茶辨别及质量控制提供科学支持和技术参考。

The aroma components of matcha powder and matcha soup were identified by electronic nose using 11 kinds of matcha as materials in order to explore the effects of different sample amount and incubation temperature on the aroma of matcha. Principal component analysis (PCA), discriminant factor analysis (DFA) and area normalization method were used to determine the optimal parameters, aroma composition and difference of electronic nose for detecting aroma of matcha. Results showed that electronic nose contributed a better distinguish for matcha powder than matcha soup. With the incubation temperature of 60 ℃ and matcha powder content of 0.5 g, the electronic nose recognition index could reach 98%, contributing the best repeatability and discrimination. A total of 259 aroma components were identified from the samples, among which, 35 kinds of aroma components were in common. The main aroma components were as follows: linalool (4.38%-9.76%)、benzyl alcohol (0.94%-2.45%)、heptyl acetate (2.26%-5.79%)、damascenone(2.32%-3.46%)、delta-valerolactone (1.21%-3.08%)、2-nonanol ( 2.33%- 5.35%)、geraniol (2.35%-6.77%)、nonanal (2.59%-4.38%)、trans-hex-2-enyl acetate (1.01%-3.86%)、( S )-(-)limonene (1.26%-2.53%)、4-methylnonane (1.0%-2.33%)、myrceneand (1.03%-2.27%), accounting for 22.68%-52.03% of the total aroma components. Overall, electronic nose can distinguish and analyze the aroma of different kinds of matcha, which provides scientific support and technical reference for the identification and quality control of matcha in the future.