DEVELOPMENT OF A CONTINUOUS MICROWAVE-BASED DRYING MACHINE FOR WITHERING PROCESS OF GREEN TEA SU Handayani(a), ME Yulianto(b), Sutrisno(c), D Ariwibowo(d), R Amalia(e), I Hartati(f)
(a-e)Vocational School, Diponegoro University, Semarang, Indonesia (f) Chemical Engineering, Wahid Hasyim University, Semarang, Indonesia
The main problem of the green tea industry today is the low quality and the high need for electrical and fuel energy of withering process (0.48 kwh / kg dry tea or 50.1% of total energy). For this reason, the development of withering process is needed through the high-efficiency agitated inactivator microwave system for producing green tea as a functional fine powder. However the development of engineering technology is still constrained by the integration of upstream into downstream energy processes. In addition, the thermal degradation of the product, caused by heat ionic conduction, penetrates to the tonoplast membrane, thus a small portion of the catechin in the vacuole will turn into theaflavin and thearubigin. Therefore, we need to study the temperature control profiling before it will be applied commercially. The results shows that the continuous microwave-based drying machine speed can be varied from 0.23 cm / s to 2.3 cm/s. The residence time in the microwave can be varied from 0.9 minutes to 9.23 minutes. While the temperature can be varied between 50 C to 120 C. The equipment can be used for withering process of green tea in accordance with the desired time and temperature. While experiments carried out for drying tea leaves give the result of drying time of 14 minutes to reach a moisture content of 0.2%.