微波制样对茶叶内质成分的影响

Effect of microwave fixation on tea chemical components

目的确定茶叶内质成分保留量最佳的微波杀青工艺参数及干燥方式。方法以夏秋茶鲜叶为研究对象,以茶多酚、咖啡碱、叶绿素、儿茶素保留量为考量指标,研究微波干燥、微波-远红外干燥、热风干燥对夏秋茶叶内质成分的影响,并对微波杀青工艺进行参数优化。通过对微波杀青时间、投叶量及微波功率进行单因素试验;并在此基础上进行L9(33)正交试验,运用方差、极差分析确定最佳微波杀青工艺参数。结果微波杀青时,投叶量50 g、微波功率800 W及微波杀青时间150 s,茶叶中内质成分保持最佳;比较三种干燥方式,得出微波干燥对茶叶内质成分在总体水平上保留效果最好。结论本研究建立的实验室微波干燥茶鲜叶方法可以为实验室微波固样方法提供参考,为工厂微波杀青及干燥提供一定的理论依据。

Objective To obtain optimum microwave parameters of both fixation and drying by measuring the index of inner components of fresh tea leaves. Methods The contents of tea polyphenols, catechins, caffeine and chlorophyll in tea were chosen as main indexes to study the effect on chemical components by different drying methods(microwave drying, microwave far infrared drying and hot-air drying) and the microwave fixation process parameters were optimized. Based on the single factor experiments of the microwave blanching time, leaf weight and microwave power and further orthogonal experiment L9(33), optimal parameters of microwave fixation process were determined by variance and range analysis. Results The optimal parameters of microwave fixation process for the best chemical components reserving was leaf weight 50 g, microwave power 800 W and microwave blanching time 150 s. Comparing the efficient of three drying methods on the best reserving of tea chemical components, the microwave drying was the best choice. Conclusion This microwave fixed method for fresh tea leaves can provide a reference for laboratory microwave fixed method and partly provide theoretical foundation for microwave fixation and dryness of fresh tea leaves for factories.