Microbial xylitol production from corn cob using Candida guilliermondii

Xylitol is a polyol that is widely used in the food industries as an alternative sweetener due to some health benefits. The microbial production of xylitol based on corn cobs was potential to be developed due to the abundant availability of corn cobs in Indonesia. In addition, it is an alternative process that is a higher yield and environmentally friendly. This study was conducted to assign the optimum process in the xylitol production based on corn cobs using Candida guilliermondii. The hydrolysis of corn cobs used sulfuric acid 1% at a temperature of 121°C for 60 minutes. The hydrolysate was then added with calcium hydroxide and activated charcoal to remove inhibitors. The design of experimental used was a factorial completely randomized design with three factors included corn cobs hydrolysate concentration (50% and 66%), glucose (0 g l^-1 and 5 g l^-1), and incubation period (120 h and 168 h). The result showed that concentration of hydrolysate, glucose, and incubation period had an effect on the xylitol produced. The highest xylitol was 144.09 ppm that was produced by the hydrolysate of 66%, glucose of 5 g l^-1 and incubation period of 168 h, meanwhile the residual xylose was 2081.87 ppm.