PENURUNAN SIANIDA UMBI GADUNG DENGAN PROSES LEACHING DAN PENGUKUSAN SEBAGAI BAHAN DASAR TEPUNG

Abstract

Dioscorea Hipida Dennst known as gadung is the tuber plant that can be found easily in Indonesia. It contains much more carbohydrate than the other one but it is not used to produce starch yet. This is because it has cyanide content and need a certain processes to make it consumable. Combination of leaching and steam process can be used to reduce cyanide from the tuber. On this research, we use 500 mg tuber and size of gadung (8 cm x 2 cm x 0.2 mm) as constant factor, while water flowrate (0.5, 2, and 3 litre.minutes), leaching time (0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, and 5 hours), and steaming time (15, 30, 45, 60, 75, 90, 105, and 120 minutes) as variables. Based on research result obtain that , the best operation conditions for leaching process are 3 litres/minutes of water flowrate and 3 hours of time leaching process, while the best condition for steaming is 75 minutes. This combination process can reduce cyanide content to 20.37 mg/kg of tuber weight in starch.