1995 Volume 25 Issue 4 Pages 191-199
This research work investigated the effect of low oxygen and high carbon dioxide atmosphere on the respiration rate and polyphenoloxidase (PPO) activity that were the main factors in fresh shiitake quality decay. Fresh Shiitakes were stored in CA conditions conducted in 2 research periods, i. e. CO2: 20% mix to O2: 10%, 5%, and 1%; and O2: 1% mix to CO2: 5%, 10%, and 15%; normal air treatment as control, and temperature 0°C and 5°C.
Decreasing O2 concentration to 1% and/or increasing CO2 to 20% decreased the respiration rate more than normal air during storage period. Both of given gas treatments were either the lower the O2 concentration or the higher the CO2 concentration the lower the respiration rates. Moreover RQ was founded close to 1 in normal air treatment after first fifth day, however RQ was less than 1 for given gas treatment. PPO Activity increased in normal air and decreased in gas treatments during storage. Discrimination of CO2 concentrations in constant low O2 concentration have firm effect on PPO activity in fresh shiitakes than that's discrimination of O2 in high CO2 concentration. Given gas treatments hold real pH of fresh shiitake did not decrease during storage.
