2007 年 17 巻 1 号 p. 57-63
We studied the lethal action of compressed oxygen gas on yeast cells and discussed its application to the sterilization processing of sudachi juice. The yeast cells (Candida boidinii SYM-1) suspended in sudachi juice could be sterilized completely when treated under the following conditions: 5.0 MPa for 15 min at 30°C, 10.0 MPa for 5 min at 40°C, and 5.0 MPa for less than 1 min at 50°C. Sudachi juice was sterilized by the treatment at 50°C without loss of vitamin C content. The removal of dissolved oxygen in sudachi juice by nitrogen gas pressurization was examined. The direct pressurization of sudachi juice with nitrogen gas decreased the amount of dissolved oxygen in it. When sudachi juice was compressed directly with nitrogen gas, more oxygen could be eliminated by applying higher nitrogen gas pressure and by taking longer time. Repetition of pressurization and depressurization with nitrogen gas could shorten the time to remove oxygen.