OBTAINING SOLUBLE AND INSOLUBLE FIBER FROM SUGARCANE BAGASSE FOR USE AS AN INPUT IN FOOD PRODUCTION

Sugarcane bagasse, an abundant byproduct of the sugar and ethanol industry, represents approximately 30% of the plant's mass. This lignocellulosic biomass is composed of 32-48% cellulose, 19-24% hemicellulose, 23-32% lignin, and 3.2-5.5% ash. This byproduct appears promising for obtaining high-value dietary fiber, including insoluble fibers such as cellulose and soluble fibers such as xylans and xyloligosaccharides (XOS), the latter with recognized prebiotic properties. This study aimed to obtain soluble (XOS) and insoluble (cellulose) dietary fiber from sugarcane bagasse, comparing the efficiency of two pretreatments: autohydrolysis (AH) and organosolv (OS). The bagasse was subjected to HA and OS pretreatments, followed by two grinding conditions (ground and unground). Subsequently, a delignification step was performed with NaClO₂ and acetic acid. The resulting solid fraction was subjected to alkaline hydrolysis with 10% NaOH to separate the cellulose (insoluble) from the xylan (soluble). The xylan in the supernatant was precipitated with ethanol and hydrolyzed with the enzyme Pentopan® Mono BG to obtain the XOS. The cellulose was characterized for yield and purity according to National Renewable Energy Laboratory (NREL) procedures, while XOS was quantified indirectly by measuring reducing sugars using the 3,5-dinitrosalicylic acid (DNS) method. The OS process demonstrated superiority over HA under both grinding conditions. The process yield was greater than 75% for OS, compared to less than 50% for HA. Cellulose characterization also revealed higher purity (higher than 90%) in the OS pretreated bagasse. The results indicate that OS pretreated bagasse was more effective in deconstructing the biomass, facilitating access to the xylan and the subsequent xylan hydrolysis to XOS (13.49 g/L to unground bagasse and 7.14 g/L to ground bagasse). Its greater efficiency in removing lignin and hemicellulose explains the higher yields and purity of the cellulose, as well as the greater release of xylans that are enzymatic hydrolysis to XOS. The adopted methodology demonstrated potential for producing high-value-added dietary fibers, highlighting the technical feasibility of using this agroindustrial residue, which adds value to the production chain and promotes a circular economy.