杀青方式对秋季黄金芽绿茶品质的影响

该研究以秋季黄金芽鲜叶为原料加工绿茶，比较滚筒、蒸汽和微波三种不同杀青方式对其品质的影响。感官评估结合品质成分分析表明，三种杀青方式所制秋季黄金芽绿茶均品质优异，但不同杀青方式处理的茶叶色泽、香气、滋味存在较大差异。滚筒杀青处理的干茶色泽最绿，香气最优，栗香明显，氨基酸含量比蒸汽和微波杀青分别高11.01%和5.20%，茶多酚含量低3.54%和3.94%，滋味醇和鲜爽；蒸汽杀青处理后滋味得分最高，拥有最高的茶氨酸（7.69 mg/g）和最低的咖啡碱（27.91 mg/g），同时电子舌结果表明，其鲜味值、丰度均最大，苦味值最小；电子舌滋味属性与化学成分相关性分析表明，秋季黄金芽绿茶茶汤鲜味值与茶氨酸含量有显著正相关（p<0.05），相关系数为0.99；苦味值与苦味儿茶素含量有显著正相关性（p<0.05），相关系数为0.99；此外，不同杀青方式的黄金芽绿茶对不同自由基的清除能力不同，总抗氧化能力依次为微波杀青（0.83）>蒸汽杀青（0.80）>滚筒杀青（0.66）。综上所述，滚筒杀青滋味醇和，香气高长；蒸汽杀青滋味醇厚，色泽黄绿。虽有所侧重，但所制秋季黄金芽绿茶均体现了其良好的品种优势。

Effects of Fixation Methods on the Quality of Huangjinya Green Tea Produced in Autumn

In this study, the fresh leaves of Huangjinya green tea obtained in Autumn were used as the raw materials to process green tea, and the effects of three different fixation methods, drum rolling, steaming and microwaving, on the quality of Huangjinya green tea products were studied. The sensory evaluation combined with quality analysis revealed that the Huangjinya green tea products produced with the three different fixation methods were all of excellent quality, but there were great differences in tea color, aroma and taste. The dry tea fixed by drum rolling had the greenest color and best aroma with an obvious chestnut aroma. Compared with thosed fixed by steaming and microwaving, the tea fixed by drum rolling had a higher amino acid content (increased by 11.01% and 5.20%, respectively) and lower content of tea polyphenols is (decreased by 3.54% and 3.94%, respectively), making the green tea taste mellow and fresh. The tea fixed by steaming had the highest taste score with the highest theanine content (7.69 mg/g) and the lowest caffeine content (27.91 mg/g), and exhibited the highest umami taste and abundance but lowest bitterness in the electronic tongue analysis. The correlation analysis of taste attributes detected by the electronic tongue and chemical composition showed that the umami value of the Autumn Huangjinya green tea was significantly and positively correlated with the theanine content (p<0.05), with the correlation coefficient as 0.99. There was a significant positive correlation between the bitterness value and the bitter-tasting catechin content (p<0.05), with the correlation coefficient as 0.99; In addition, the Huangjinya green tea fixed with different methods had different abilities to scavenge different free radicals, with the total antioxidant capacity decreased in the order of microwaving (0.83) > steaming (0.80) > drum rolling (0.66). In summary, the tea fixed by drum rolling tastes mellow with a strong and long aroma; the tea fxied by steaming had a mellow and thick taste and yellow-green color. Although there are some distinct favorable attributes, the Huangjinya green teas all show variety advantages.