METHOD FOR DRY BLACK TEA TREATMENT Russian patent published in 2020 - IPC A23F3/06 

FIELD: tea industry.

SUBSTANCE: tea leaves wilting to moisture content of 75–65 %, twisting, fermentation and drying till residual moisture content is less than 10 %. Secondary drying is carried out by means of thermal exposure to UHF electromagnetic field in drying chamber for 8–12 min with constant pressure in drying chamber, selected from the range of values of 50–60 kPa. Dry black tea is heated to 70.0–80.0 °C. Rate of temperature growth in drying chamber under action of electromagnetic microwave field is selected from range of values of 1.0–3.0 °C/s. After achieving the specified temperature value and after the thermal action time termination, the thermal exposure to the electromagnetic microwave field with simultaneous transition into pressure reduction mode in chamber to a value selected from range from 14 kPa to 4 kPa. Dry black tea is held in the chamber at decreasing pressure until its temperature drops to the temperature of the production room, in which drying chamber is installed.

EFFECT: invention ensures preservation of maximum quantity of useful substances in dry black tea: up to 60 % of vitamins, up to 40 % of alkaloids, up to 50 % of proteins and amino acids, organoleptic properties, with simultaneous reduction of microbial load on dry black tea.

1 cl, 3 ex