Optimization of the fermentation process in the manufacture of modified porang flour using the biologically modified cassava flour starter

One method that can be developed to improve the quality of porang flour is through a fermentation process using the biologically modified cassava flour (Bimo CF) starter, which consists of a carrier material and an active ingredient of lactic acid bacteria. This research was conducted with the aim of studying the optimum concentration of Bimo CF starter and the fermentation time used in processing porang flour. The research was conducted using the response surface methodology (RSM) with a 3-level factorial design. The lower and upper limits for Bimo CF starter concentrations were 0.1 and 0.5%, and 12 and 24 h for fermentation time, respectively. The results of the research showed that the responses that are significantly influenced by the applied independent variables include: protein, fat, starch, crude fiber, calcium oxalate, glucomannan, and yield. Whereas the response of moisture, ash, and whiteness levels was not significantly affected. Optimization results showed that the concentration of Bimo CF starter and the optimum fermentation time were 0.5% and 20 h, respectively, with a level of desirability of 0.91%. The verification results showed that the calcium oxalate levels were far below the predicted value, which was half of the predicted value. Likewise, the glucomannan content showed a value far above the predicted value. This indicates that the optimum fermentation process obtained from this study can be developed to produce modified porang flour with low calcium oxalate and high glucomannan.