Effect of Rice-Bran Pretreatment in Biohydrogen Production

This study investigated the effect of different pretreatment methods on sugar liberation from Rice bran (RB) and Deoiled Rice bran (DRB). An amount of 100 g of RB or DRB were soaked in 1% (w/v) trichloroacetic acid (99.0 % stock concentration) separately and each mixture was made up to 1L with distilled water to generate the Acid treated RB hydrolysate (ARB) and acid treated DRB hydrolysate. RB and DRB were also subjected to a combined treatment of acid, hydrothermal (boiling) and enzyme treatments to investigate the effects of the combination of the three different methods. Sugar compositions of pretreated samples were determined using high-performance liquid chromatography. It was that there was an increment of more than 400 % and 300 % respectively in the concentration of sugar obtained from acid treated RB and DRB hydrolysates over the untreated RB and DRB hydrolysates. In combined treatment, RB hydrolysates showed an increment of 584% in the amount of total sugar released as well as 500 % increment in DRB hydrolysates. The amount of sugar liberated from DRB hydrolysates is slightly more than the respective RB hydrolysates subjected to same treatment. The increase in the amount of rice bran hydrolysates produced demonstrated that pretreatment of Rice bran with acid, boiling and via enzymatic reactions can increase the amount of biohydrogen produced.