Orange biomass by-products

Abstract

Brazil is the major orange producer in the world that per year counts on about ten million tons of underutilized waste (orange biomass). This biomass has a great potential for ethanol production through the hydrolysis of its high amount of polysaccharides with low cost enzyme cocktails. For this purpose, an enzymatic cocktail of cellulases (FPU 8 mL-1) and pectinases (58 U g-1) from Xanthomonas axonopodis pv. citri bacteria was used for the hydrolysis of orange bagasse, thus being able to substitute the use of commercial enzymes, which involve a high cost in an industrial scale. The second phase of the proposed bioprocess for second-generation ethanol from orange biomass is called fermentation with co-cultures, and it ensured the conversion of almost 100 % of the sugars. Hesperidin and nanocellulose were also obtained from bagasse. The hesperidin (1.2 % yield) was obtained in two steps, by liquid-solid extraction and purification, while nanocellulose (1.4 % yield) was obtained through a procedure of extraction, bleaching and nanonization.