Unlike other tea products, matcha is grind directly from tea shoots with L-theanine and chlorophyll content accumulated in the period before harvesting, which is very sensitive to temperature drying. If it is dried at high temperature, L-theanine and chlorophyll content will be largely lost. Matcha and green tea powder are just the same. Heating pump drying is one of the advanced drying technology solutions with lower drying temperatures below 60°C. At this temperature rank, the speed of chemical reactions that reduce the quality while preserving distinctive color of the product is limited. Orthogonal symmetry was used in this study with 3 factors influencing the heat pump drying method including temperature and speed of the drying agent, and the thickness of the tea layer with 2 objective functions: L- theanine and chlorophyll. Optimizing the study by using algorithm "desirability", and heat pump drying method with optimal mode: drying agent temperature of 30.C, the tea layer thickness of 20 mm, and drying agent speed of 1.25 mis, the results showed that the dried tea remained really high content of L- theanine with 24.76 mg/ g and chlorophyll with 79.28 mg/ g. Comparing the content of L- theanine and chlorophyll before and after the process, the results showed that it was preserved 97.4 percent and 94.65 percent respectively. The dried tea product has as distinctive bright green color as matcha.
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