Sunflower Meal Valorization through Enzyme-Aided Fractionation and the Production of Emerging Prebiotics

Abstract: Recently, there has been a burgeoning interest in harnessing the potential of biomass
and industry byproducts for the development of novel products and materials. In particular, this
study explored the efficient valorization of sunflower meal (SFM), an underutilized byproduct of
the oil extraction industry, usually discarded or used as low-value animal feed through enzymeaided fractionation, specifically targeting the extraction and conversion of its abundant carbohydrate
component, xylan, into emerging prebiotic compounds—xylo-oligosaccharides (XOSs)—which are
recognized as promotors of a healthy gut microbiome and overall human wellbeing. An enzymatic
treatment using Alcalase® 2.4 L was implemented for facilitating the recovery of a highly pure
hemicellulosic fraction (92.2% carbohydrates) rich in β-(1→4)-linked xylose residues with arabinose
and glucuronic acid substitutions (DP-xylan). A further enzymatic treatment of this substrate,
using ROHALASE® SEP-VISCO under optimized conditions (70 ◦C, pH 6, 0.005% v/v enzyme
concentration), produced 52.3% of XOSs with a polymerization degree (DP) less than 20 after two
hours. Further analyses demonstrated that the majority of the obtained product had a DP less
than 6, predominantly consisting of di- and trisaccharides (XOS2 and XOS3) without the significant
generation of xylose. These findings highlight the significant potential of SFM for the generation of
valuable prebiotic compounds in a sustainable manner.
Keywords: sunflower meal; byproduct valorization; enzyme-aided fractionation; xylo-oligosaccharides;
emerging prebiotics