In this study, unmodified, amino modified and cyanuric chloride functionalized amino modified nonporous fumed nano-silica particles (FNS, AFNS and CCAFNS, respectively) were used for the development of efficient nanobiocatalysts for application in the biosynthesis of bioactive galactosides, galacto-oligosaccharides (GOS). Hence, in an attempt to elucidate the mechanism of immobilization, based on available enzyme conformation, the effects of immobilization parameters (initial enzyme concentration, immobilization time and pH) were analyzed. Among all three used nano-sized supports, the one with amino groups (AFNS) exhibited the best β-galactosidase binding capacity of 220 mg g⁻¹ support with the efficiency of ∼90% at pH 4.5 and immobilization time 3 h. The highest hydrolytic activity of ∼2200 IU g⁻¹ was achieved, which is far higher than previously reported. Meanwhile, β-galactosidases covalently immobilized on CCAFNS and adsorbed on FNS nanoparticles were found to have similar trends with respect to immobilization efficiency (58–71%) and hydrolytic activity (∼600 IU g⁻¹). Furthermore, thermal stability at 60 °C was increased by β-galactosidases immobilized on AFNS and CCAFNS (4 and 1.4-fold, respectively) due to the protective effect of interactions formed between enzyme molecules and the surfaces of nanoparticles. Since β-galactosidase immobilized on AFNS was the nanobiocatalyst with the highest activity and stability, it was applied in GOS production. With AFNS–β-galactosidase GOS production of 90 g L⁻¹ h⁻¹ was achieved as compared to 30 g L⁻¹ h⁻¹ by free β-galactosidase, meaning that AFNS enhanced the selectivity of β-galactosidase for transgalactosylation, which is a crucial advantage for its application in GOS production.

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.

This review highlights the enzymatic advances in the synthesis of emerging prebiotics, focusing on improved control, biocatalyst enhancement, and bioprocess intensification.

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.