扁形绿茶降苦涩关键工艺优化及品质分析

为优化单芽扁形绿茶的杀青、足火（干燥）工艺并降低其苦涩度，以感官审评的滋味得分、茶汤苦涩味和干茶色泽为评价指标进行单因素试验；在此基础上，以感官审评的滋味得分、酚氨比、可溶性糖含量、儿茶素总量以及儿茶素苦涩味指数为评价指标进行正交试验。结果表明：单芽扁形绿茶的杀青最佳工艺参数为：杀青前茶坯含水量74%、杀青温度320℃、杀青时间8 min；足火前茶坯含水量15%、足火温度80℃、足火时间40 min。相比采用传统工艺加工的单芽扁形绿茶，利用优化工艺加工的单芽扁形绿茶感官审评滋味评分提高了4分，酚氨比降低了0.222，可溶性糖含量增加了1.376%，儿茶素总量增加了5.7%，苦涩味指数降低了1.12。该结果为扁形绿茶标准化生产工艺的制定提供理论支撑。

Quality Analysis and Optimization of Key Processing Technology to Reduce Bitterness of Flat Green Tea

In order to optimize the process of pan-fire and second-drying of single-bud flat green tea and reduce its bitterness of taste, a single factor test was carried out with the taste score of sensory quality, bitter taste of tea soup and dry tea color as evaluation indexes. On this basis, orthogonal experiments were carried out with the taste score of sensory evaluation, phenol-ammonia ratio, soluble sugar content, catechin total and catechin astringency index as evaluation indexes. The results showed that the optimum pan-fire conditions were the water content of 74%, pan-fire temperature of 320℃, pan-fire time of 8 min; and the optimum second-drying conditions were the water content of 15%, second-drying temperature of 80℃, second-drying time of 40 min. Compared with single-bud flat green tea processed by traditional technology, the taste score of sensory evaluation of single-bud flat green tea processed by optimized technology increased by 4 points, the phenol-ammonia ratio decreased by 0.222, the soluble sugar content increased by 1.376%, the total catechin increased by 5.7%, and the bitterness index decreased by 1.12. The result provides theoretical support for the formulation of standard technology of flat green tea.