咖啡中关键香气化合物的萃取动力学分析  

Extraction Kinetics of Key Aroma Compounds in Coffee Brews

作　　者：杨习文 陈茂深[1] 钟芳[1] YANG Xiwen;CHEN Maoshen;ZHONG Fang(School of Food Science and Technology,Jiangnan University,Wuxi 214122,China)

机构地区：[1]江南大学食品学院,江苏无锡214122

出　　处：《食品与生物技术学报》2022年第9期20-29,共10页Journal of Food Science and Biotechnology

基　　金：中央高校基本科研专项(JUSRP52029A)。

摘　　要：为探究萃取过程中各阶段咖啡液的香气化合物组成与质量分数的动态变化规律,选用危地马拉咖啡豆,连续恒压900 kPa萃取咖啡液,并采用顶空固相微萃取-气质联用法测定咖啡液香气化合物的质量分数。结果表明,挥发性关键香气化合物的恒压萃取进程符合幂定律方程,极性是决定动态萃取速率的关键因素。萃取初期,2-甲基吡嗪等强极性物质的萃取速率常数是弱极性物质β-大马酮的7~35倍;萃取末期,弱极性物质的总质量分数由20%增加至30%,香气平衡改变。连续萃取过程中,关键化合物的香气活度值在浅度和中度烘焙咖啡中的下降速率高于深度烘焙咖啡。基于实验数据并结合精品咖啡协会金杯萃取规则,研究提出:为获得滋味和香气平衡度更佳的咖啡萃取液,浅度和中度烘焙咖啡可控制在每17 g咖啡粉萃取杯量为30~40 g,深焙咖啡则可以适当增加至每17 g咖啡粉萃取杯量40~50 g。This research aimed to explore the dynamic changes of aroma compounds composition and mass fraction of coffee brews at different stages of extraction process.The roasted Guatemalan coffee beans were selected to prepare coffee brews under a continuous constant pressure 900 kPa extraction.The HS-SPME-GC/MS method was used to study the mass fraction of aroma compounds in coffee brews.The results showed that the constant pressure extraction process of key volatile aroma compounds conformed to the Power Law equation,and the polarity was the key factor that determined the dynamic extraction rate.In the initial stage of extraction,the extraction rate constant of strong polarity substances such as 2-methylpyrazine was 7 to 35 times that ofβ-damascone with weak polarity.At the end of extraction,the total mass fraction of weak polarity substances increased from 20%to 30%,and the aroma balance changed.During the continuous extraction process,the odor activity value of key compounds in light and medium roasted coffee decreased faster than that in dark roasted coffee.Based on the experimental data,combined with and concerned about the Golden cup extraction regulations formulated by the Specialty Coffee Association,the study proposed that in order to obtain a cup of coffee with a better balance of taste and aroma,the cup extraction could be controlled to 30~40 g of 17 g coffee powder for light and medium roasted coffee,and 40~50 g of 17 g coffee powder for dark roasted coffee.

关 键 词：浓缩咖啡 香气化合物 HS-SPME-GC-MS 萃取动力学 香气活度值 烘焙程度 

分 类 号：TS273[轻工技术与工程—农产品加工及贮藏工程]