초록
<P><B>Abstract</B></P> <P>An underutilized residue called Citrus Pulp of Floater (CPF), which causes problems during the industrial process of manufacturing of orange juice, was explored for the production of high value-added products. Mixed, first (1G) and second generation (2G) ethanol, a clean and renewable biofuel, was obtained after an enzyme cocktail isolated from the <I>Xanthomonas axonopodis</I> pv. <I>citri</I> (<I>Xac</I>) was applied in hydrolysis of this biomass. Then, mono- and co-culture fermentations were performed using the yeast <I>Saccharomyces cerevisiae</I> and two <I>Candida</I> strains (<I>Candida parapsilosis</I> IFM 48375 and NRRL Y-12969), where the last two were isolated from the orange bagasse <I>in natura</I>. After the enzymatic hydrolysis step, sugars obtained were converted to ethanol achieving a yield of almost 100% after co-fermentation. Hesperidin, a flavonoid widely used for its antimicrobial and/or antioxidant activities, was also extracted from CPF by liquid-solid extraction and precipitation, with the yield of 1.2% and 92.6% pure. Finally, nanocellulose was produced through processes such as extraction, bleaching and nanonization with the yield of 1.4% and over 98% of purity. These products – ethanol, hesperidin and nanocellulose were obtained from three independent processes: (1) after an enzyme-based hydrolysis of CPF, liquid part was used for ethanol production, and solid was preserved; (2) hesperidin was isolated from a dry CPF, and solid residue was preserved; and (3) nanocellulose was obtained from the solid residues after processes cited in 1 and 2.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Citrus Pulp of Floater (CPF) was explored for the production of high value-added products. </LI> <LI> Bioethanol was successfully obtained from the CPF in co-culture fermentation. </LI> <LI> Hesperidin (1.2%) and nanocellulose (1.4%) of excellent purities were also obtained from the CPF. </LI> <LI> From an underutilized biomass - CPF, at least three valuable products can be obtained. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>