基于气味在线检测的绿茶锅式杀青系统研究

Study on pot type fixation process of green tea based on online flavor detection

在传统的锅式杀青装置基础上,植入PEN3电子鼻进行气味在线检测,通过研究不同锅温下PEN3电子鼻代表性传感器响应值与杀青品质的关系,提出基于气味在线检测的绿茶锅式杀青系统,根据酶促氧化物以及绿茶香气的测量值来反馈控制杀青锅温。结果表明:杀青锅温过低会导致前期酶促氧化严重,过高会导致香气散失过多,因此在前期灭酶完成后立刻将杀青锅温降低,可提升杀青品质;对比发现杀青锅温由180℃降低到140℃的控制方案下品质最佳,此时茶多酚和氨基酸分别为20.85%和3.66%,酚氨比为5.85,氧化酶活性为5.19 U/mL。

In this study,the PEN3 electronic nose was implanted for online flavor detection,based on the traditional pot-type fixating device.By studying the relationship between the response value of the PEN3 electronic nose representative sensor and the quality of the fixating at different pot temperatures,a green tea pot-type fixating system based on the flavor online detection was proposed.The system could feedback control the temperature of the fixating pot according to the measured values of enzymatic oxides and the aroma volatiles of the green tea.The results showed that the low temperature of the fixating pot could lead to serious enzymatic oxidation in the early stage,while the high temperature caused excessive loss of aroma substances.Therefore,immediately after the completion of the elimination of oxidase,the temperature of the fixating pot should be lowered to improve the quality of the fixation;with comparison,it was found that the quality of the control program was reduced from 180℃to 140℃,and the tea polyphenols and amino acids were 20.85%and 3.66%respectively.The phenol-ammonia ratio was 5.85,and the oxidase activity was 5.19 U/mL.