GREEN TEA PROCESSING METHOD Russian patent published in 2020 - IPC A23F3/12 

FIELD: food industry.

SUBSTANCE: invention relates to the tea industry. Redox enzymes are inactivated by thermal action on green tea leaves with subsequent treatment of green tea leaves to residual moisture content of 60–75 %. Tea leaves are twisted. Drying of tea leaf is performed in two stages and tea leaf is sorted. At the first stage for 8–12 minutes the formation of tea leaves with height of not more than 10 cm, with moisture content of 60–75 % of electromagnetic microwave field, at constant pressure in drying chamber with values selected from range of 40–80 kPa, with uniform heating temperature growth rate 3–4 °C/s. Speed is selected proceeding from the necessity to reach the heating temperature values from range of 70–85 °C by the end of the first stage and taking into account duration of the first stage. At the second drying stage pulse heating is used in range of 35–45 °C by means of electromagnetic microwave field at pressure reduction in drying chamber to values of 15–4 kPa until residual moisture content is less than 10 %. Then the vacuum pump is switched off and atmospheric pressure is restored in the chamber.

EFFECT: invention ensures simplification of green tea drying technology, provision of uniform heating of each batch of tea loaded into drying chamber, prevention of caramelisation of sugars at the initial stages of drying mode, increase of green tea infusion extractiveness and improvement of its organoleptic properties.

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