Effects of storage conditions on quality of matcha [powdered tea]

The effects of different storage conditions (temperature and period) on quality of Matcha have been studied by measuring the contents of chlorophyll and its derivatives, total vitamin C, the surface color value and the amount of oxygen in tea bag. Sensory test was used at the same time. As a result, it was found that the preservation of Matcha under low temperature (-70 and 4degC) kept its quality in good conditions during 24 weeks. Furthermore, the preservation at room temperature (25degC) kept the quality in the moderate conditions during 24 weeks. However, at the higher temperature of 37degC, the quality of Matcha resulted in fairly bad in 3 or 4 weeks. The cause of the changes in quality should be related to the decrease of the amount of oxygen in tea bag at the higher storage temperatures.