GREEN TEA PRODUCTION METHOD Russian patent published in 2020 - IPC A23F3/06 

FIELD: tea industry.

SUBSTANCE: tea leaves are withered to 65–75 % moisture content. Fixation and twisting are performed. Tea leaves layer is dried in three stages in drying chamber in vacuum till content of moisture in tea leaf is up to 4–6 %. At first two stages using sources of microwave radiation. Duration of each of two first stages of drying is 25–30 minutes. First drying step is carried out at constant temperature values from range 55–65 °C and pressure from range of 170–90 mm of mercury. At second drying step, pressure is increased to values from range of 185–500 mm Hg, and temperature is to value from range of 65–89 °C and maintained temperature and pressure until transition into third stage. At the third stage, the microwave radiation source is disconnected and temperature in the drying chamber falls in passive mode to values, close to temperature in production room, and pressure is reduced to values of about 25 mm Hg. Decrease of pressure at the third stage is carried out proceeding from current values of temperature, with possibility of continuous process of steam formation in tea leaves. Duration of the third stage is selected from time intervals providing total duration of drying within 90–100 minutes.

EFFECT: invention provides higher content of chlorophyll in tea, improved organoleptic indices, according to which quality of green tea is evaluated, simplified technology of its production, increased storage life of the ready product and reduced probability of its damage by harmful bacteria.

3 cl, 4 tbl, 5 ex