The results showed that high yield and optimal product quality were achived when using an antibrowning agent of 0.2% NaHSO3; wet grinding technology in ethanol: water (1.5: 1) solvent; ratio of solvents / raw materials 2: 1, grinding time is 20 minutes; followed by filteration by membrane filter (pore size <0.15 mm); GM powder is separated by horizontal centrifugation at 500 rpm and then dried in a refrigerating equipment at 10 °C for up to 10 hours.