Effects of microwave far-infrared coupling fixation processes on quality of green tea

In order to study the influence of microwave far-infrared coupling fixation technology on the quality of green tea. The effect of fixation time, fixation power and input quantity on green tea aroma and taste quality were analyzed. Compared with other fixation methods, the microwave far-infrared coupling fixation technology of green tea was optimized through the L9 (34) orthogonal experimental design. The results showed that the fixation effects was best when fixation power of microwave was 10 kW, fixation power of far-infrared was 6 kW, and input quantity was 0.5 kg/min, and green tea was fixed for 1.5 min with microwave before fixed for 1.5 min with far-infrared. The taste and aroma of green tea was best and sensory quality slore was 91.40. And tea polyphenols, catechins, caffeine, amino acids, soluble sugar and aromatic oil quality score reached 17.24%, 12.62%, 3.10%, 3.72%, 4.64%, 15.40×10-2 mg/g, respectively. Aromatic and taste quality were better than that with the other fixation ways. The fixation time was 1/4–1/3 of the traditional heating fixation, and the energy consumption was 1/3–1/2 of the traditional heating fixation. The insufficiency of the only using microwave fixation technology could be overcome with microwave far-infrared coupling fixation technology, which will provide the reference for the green tea processing production.