| 摘要 |
PURPOSE:To carry out the removal of astringency from a large amount of persimmons, in high efficiency, by supplying a closed chamber for the removal of astringency with CO2 from its floor while discharging air from the upper part of the chamber, thereby replacing the air in the chamber with concentrated CO2 in a short time. CONSTITUTION:The heat insulation tent 3 and the airtight tent 4 in the chamber 5 for the removal of the astringency of persimmons, are rolled up with wires 18 by driving a drum 21. Containers 22 containing persimmons are placed on the supporting blocks 29 in the chamber 5, the tents 3 and 4 are lowered to close the chamber 5, and the chamber is heated with the heater 24. Then the air-exhaust hole 8 at the upper part of the chamber 5 is opened, and CO2 gas is introduced into the chamber 5 from the introduction chamber 6 placed under the floor of the chamber 5. The rate of introduction of CO2 is controlled to a low level at the initial stage, and increased according to the increase in the height of the introduced CO2 layer in the chamber 5 thereby preventing the mixing of CO2 and air. When the CO2 layer reaches the ceiling of the chamber 5, the hole 8 is closed and the removal of astringency of persimmons is carried out in the CO2 atmosphere of a concentration of as high as >=97%. After the removal treatment, the skirts of the tents 3 and 4 are rolled up to substitute CO2 with external air, and again the tents are lowered to close the chamber 5 and to accelerate the insolubilization of tannin as an auxiliary astringency removal reaction. |
