Abstract:In order to optimize the shaping and roasting process of flat green tea under the automated continuous production line，a single factor test was carried out with appearance，color and shape as evaluation indicators.On this basis，orthogonal experiments were carried out with sensory score，bulk density，-b/a value of tea infusion，and catechin quality index as evaluation indexes.The technological parameters were optimized，and the changes of quality components during the processing of flat green tea were analyzed by a combination of sensory evaluation and physical and chemical analysis.The results showed that the best technological parameters for the shaping process were leaf casting amount of 75 g，shaping time of 75 s，and shaping temperature of 220℃，and the best technological parameters for the drying process were leaf casting amount of 60 g，shaping time of 160 s，and shaping temperature of 160 ℃.A series of changes had taken place in the physical and chemical composition of flat green tea.The moisture content，water extract，tea polyphenols and caffeine content of tea product showed a continuous decreasing trend，and the total free amino acid first decreased and then increased.The content of free amino acids was the lowest in the finishing process.The soluble sugar content reached the highest level in the frying process.Compared with traditional flat green tea，the sensory score of optimized flat green tea increased by 2.27 points，the bulk density of tea increased by 10.84%，the tea soup color and catechin quality index were significantly improved.