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 enzyme-aided 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.

Blackcurrant pomace is a widely available waste stream derived from the industrial production of juice rich in pectin and unextracted polyphenols. Since pectin, an emerging class of gastrointestinal prebiotics, is also a common cosmetic ingredient, the aim of this work was to evaluate blackcurrant pomace as a source of pectin-rich fractions suitable for application in prebiotic cosmetics. Hereby, this raw material was valorised by sequential extraction of acid-soluble (by citric acid, CAP) and Ca-bound (by ammonium oxalate, AOPP) pectic polysaccharides. Both fractions had favourable physicochemical features and a similar degree of methyl-esterification between low- and high-methoxyl pectin (approx. 50%), but CAP had significantly higher galacturonic acid content (72.3%), branching, and purity. Regardless of that, both had very high oil (18.96 mL/g for CAP and 19.32 mL/g for AOPP) and water (9.97 mL/g for CAP and 7.32 mL/g for AOPP)-holding capacities and excellent emulsifying properties, making them promising cosmetic ingredients. The polyphenol content was 10 times higher in CAP, while corresponding antioxidant activity was 3-fold higher. Finally, the influence of varying CAP and AOPP concentrations on common skin pathogen, Staphylococcus aureus, and beneficial skin bacteria, Staphylococcus epidermidis, was examined. The results show significant prebiotic potential of two pectic fractions since they were capable of selectively stimulating S. epidermidis, while S. aureus growth was inhibited, whereas CAP demonstrated a particularly high capacity of up to 2.2, even with methicillin-resistant S. aureus.

In this study, a heterofunctional carrier was obtained by modification of a macroporous polystyrene ion exchange resin with primary amino groups (Purolite® A109) with epichlorohydrin, in view of achieving covalent immobilization of fructosyltransferase (FTase) from a complex enzyme mixture, Pectinex® Ultra SP-L, that is responsible for the synthesis of functionally active fructo-oligosaccharides (FOS). A two-step immobilization protocol, comprising the physical adsorption of FTase performed at pH 4 and subsequent buffer exchange to promote the establishment of covalent bonds at pH 9, was proposed for obtaining a highly active immobilized preparation (243 IU g⁻¹ of support). Additionally, this protocol provided development of a preparation with 20 times more prominent expressed activity of FTase compared to the commercial preparation with predominant pectinase activity. The obtained immobilized preparation was further tested in batch and air-lift reactor systems for FOS synthesis, yielding 52.8% and 54.7% of FOS in total carbohydrates, respectively. Finally, the continuous production of FOS in the air-lift reactor was established for 7 days, with an average FOS yield of 52.5%. Accordingly, it is demonstrated that the immobilization process enabled the development of preparations with exceptional potential for industrial implementation.

This study investigates the extraction of pectic polysaccharides from rapeseed meal (RSM) using both conventional and enzyme-assisted techniques, and the obtained pectic polysaccharide fractions will be used later to produce prebiotic pectic oligosaccharides (POS). A two-step process was developed, involving enzymatic treatment with Alcalase^® 2.4 L for 2 h and Cellic^® CTec3 HS preparations for 24 h, followed by ammonium oxalate extraction, which effectively isolated two pectic polysaccharide-enriched fractions: PP-EAE (first step) and the resulting Ca-bound pectic polysaccharides fraction (CaPP-EAE) (second step). Both fractions exhibited a bimodal molecular weight profile, indicative of the presence of long-chain polysaccharides alongside oligosaccharides. CaPP-EAE compositional analysis revealed that the fraction contained 56.8% galacturonic acid (GalA), low methyl-esterified (LM) pectins with 53.2% homogalacturonan (HG) and 30.2% rhamnogalacturonan I (RG-I) domains, featuring side chains of arabinan, arabinogalactan, and galactan. Subsequent enzymatic treatment with 0.5% (v/v) of Pectinex^® Ultra Passover for 30 min transformed these fragments into a mixture of short-chain POS. Importantly, the produced short-chain POS fraction demonstrated enhanced prebiotic activity, particularly for bacterial strains of the family Lactobacillaceae, compared to a yeast strain. These findings provide a sustainable, biorefinery-compatible approach for extracting and modifying RSM polysaccharides, supporting the development of structurally defined POS as novel prebiotics.