杀青及干燥工艺对碾茶品质的影响

杀青和干燥是碾茶加工的两个关键工序,为提高碾茶(抹茶)品质,通过研究300K-SS型碾茶蒸机(杀青机)的转速、蒸汽流量和AYHF-450K型碾茶烘房(干燥机)燃烧温度等关键工艺参数,分别探讨对碾茶感官品质、理化成分等的影响;并运用偏最小二乘判别分析(Partial Least Squares Discriminant ...

Effects of Fixing and Drying Processes on the Quality of Tencha

Fixing and drying are two key processes in Tencha processing,in order to improve the quality of Tencha (Matcha),the effects of key process parameters,such as rotation speed,steam flow rate of 300K-SS Tencha steamer (fixation machine) and combustion temperature of AYHF-450K drying room (dryer) on the sensory quality and Main chemical composition of Tencha were studied.Partial least squares discriminant analysis (PLS-DA) was used to study the key difference components in the process parameters of fixing and drying.The results showed that the Tencha processed with 400 rpm/40 rpm speed of fixation steaming cylinder had green appearance,bright green tea soup,low content of caffeine and ester-catechin,fresh taste and better comprehensive quality.The amino acid content (4.75%) of Tencha processed with steam flow rate of 110 k·h-1 was significantly higher than that of the other flow rates,the ratio of phenol to ammonia was the smallest,the taste of tea soup was fresh,the balance of bitter and astringent taste was better,and the absolute value of tea hue (b * / A *) was the smallest,indicating that its color greenness was high;The Tencha dried by 250 ℃ combustion machine had the highest sensory evaluation score,the smallest phenol ammonia ratio and the smallest ratio of ester and non-ester catechin,and the taste of tea soup was relatively harmonious and pure,and the chlorophyll in the fresh leaves was well preserved,which made the tea and tea soup appear more green color.PLS-DA distinguished the Tencha processed with change of the three processing conditions,and the quality indexes such as phenol ammonia ratio,ester / non ester catechin and free amino acid content were quite different in Tencha processed under different processing conditions.In addition,drying temperature may be the most critical process during Tencha processing according to the loading plot of PLS-DA model.This study is helpful to optimize the key process parameters in the processing of Tencha,improve the quality of Tencha (Matcha) and guide the actual production.