栗香绿茶香气萃取方法优化及其芳香成分分析

以14个具典型栗香特征和2个甜香特征的绿茶茶样为研究对象,比较了固相微萃取头种类、萃取温度、萃取时间及电解质浓度对栗香香气物质种类和总量的影响,探索萃取栗香绿茶香气物质的适宜条件,并开展栗香绿茶的特征峰分析。结果表明,采用DVB/CAR/PDMS固相微萃取头,在50℃下吸附50βmin,电解质浓度控制为1~3βmg·mL^-1时,能达到最佳的吸附效果;在该条件下,共检测出171种挥发性化合物,筛选出30个峰为栗香绿茶的共有特征峰,其中醇类5种、烯烃类4种,烷烃类7种,且各色谱峰相对峰面积的RSD≤5.0%,显示其具有较好的重复性。通过夹角余弦法和相关系数法进行相似度分析,证实栗香特征峰具有较好的解释能力。

Optimization of Aroma Extraction and Aroma Component Analysis on Chestnut-like Green Tea

Fourteen green tea samples with typical chestnut-like aroma and 2 samples with sweet aroma were used as materials and the optimal conditions including the type of extraction fiber, the extraction time, the extraction temperature and electrolyte concentration were selected by comparing the extraction effect of different conditions. The optimal conditions for preparing aroma of chestnut-like green tea were explored and the characteristic peak analysis of chestnut-like green tea was carried out. Results indicated that the optimal extraction conditions of chestnut-like green tea were as follows: extraction fiber DVB/CAR/PDMS, extraction temperature at 50℃, extraction for 50βmin, electrolyte concentration of 1-3βmg·L^-1. under this condition, 171 volatile compounds were detected and 30 peaks were identified as common characteristic peaks of chestnut-like green tea, including 5 alcohols, 4 alkenes, 7 alkanes. the RSDs of the relative peak areas were ≤5.0%, which showed a high repeatability. The similarity analysis of angle cosine method and correlation coefficient method proved that the characteristic peaks could well explain their contribution to chestnut-like fragrant.