Removal of Cyanides from Gadung (Dioscorea hispida Dennst.) Tuber Chips using Leaching and Steaming Techniques

Abstract

Gadung (Dioscorea hispida Dennst.) has been considered as one of staple foods in Indonesia. However, its high cyanides content has limited its utilisation for commercial food production. This work is aimed to investigate the removal of cyanides content from gadung tuber chips through two consecutive treatments, i.e. leaching and steaming and to propose mathematics model for the leaching process. The results showed that processing water flow rate and leaching time affected the efficiency of cyanides removal in the leaching process. The proposed mathematical model was able to represent the removal of cyanides through leaching process very well. The cyanides content removal was also found to be affected by steaming time. Best processing condition was at leaching using 5.00  10-5 m3.s-1 for 3,600 s, followed by steaming for 3,600 s to obtain cyanides content of 29.9 mgkg-1. While the yielded gadung tuber chips are considered as safe for consumption, further research on physicochemical characteristic of the gadung tuber flour is necessary for its utilisation consideration.