Improvement the Chemical Properties of Cassava Through Microbial Fermentation Using Rhizopus Oligosporus

¹ Departement of Mechanical Engineering, Semarang State Polytechnic, Postal Code 50275, Semarang, Indonesia
² Department of Chemical Engineering, Diponegoro University, 50275, Semarang, Indonesia

^* Corresponding author: tprasetyo06@yahoo.com

Abstract

Indonesia is the world’s largest importer of wheat. Because of high wheat imported, Indonesia’s researchers has seek an alternative to wheat-based local materials that having equivalent physicochemical properties. Potential alternative replacement of wheat flour is cassava. Cassava can be modified its rheology and physicochemical properties in order to be wheat equivalents. Cyanide contained in the cassava flour cannot be removed immediately by physical treatment. Several efforts have been made, such as soaking with saline solution, the addition of citric acid, and heating, showed a reduction in levels of cyanide in the flour. In this study, reduced levels of cyanide bound by converting it into protein using of Rhizopus oligosporus. While cyanide dissolved with the help of soaking with saline solution and buffer solution. In this case, use a buffer solution such as sodium sulphites which serves to change the form of cyanide dissolved into a form that is less toxic. In addition, a buffer solution pH also controls a range of 6, because in this range of cyanide bound to be easier to dissolve. With the combination treatment is expected to be a reduction in the levels of cyanide and exhibited significantly increased levels of protein in cassava flour. Flour has a protein content of best nutritional protein at 3.68 % dry basis. Cyanide reduction was highest in samples with high levels of Rhizopus oligosporus grated 1.5% (w/w) as 72 hours, with a lag of 0.09 (mg/kg) cyanide. Flour with the best nutritional quality is obtained from fermentation with conditions: grated, 12 hours of fermentation as well as using Rhizopus oligosporus 3.5% (w/w).