Effects of baking treatment on the sensory quality and physicochemical properties of green tea with different processing methods

Seven batches of raw tea leaves, processed by different methods (steaming, pan-frying) and from two different harvesting seasons (spring, autumn), were used to investigate the effect of baking treatment on changes in the composition and content of nonvolatile and volatile compounds. The results showed that baking had a greater impact on sensory and flavor quality, which chemically modified some of taste and aroma components. The aroma concentrations of steamed teas (4,168-10,706 μg/L) were significantly higher than those of pan-fried teas (959-2,608 μg/L), and the aroma concentrations of baked green teas (2,608-10,706 μg/L) were significantly higher than those of unbaked teas (959-4,213 μg/L). Based on VIP > 1 and ACI > 1, (E, E)-3,5-octadien-2-one, hexanal, β-ionone, 5-methylfurfural, β-cyclocitral, and linalool were identified as the main aroma compounds. Chemical changes resulting from Maillard reaction were greater during baking of steamed, than pan-fried green tea. These results help improve the quality of green tea with baking.