In the present study water extractable arabinoxylans (WEAX) from a Mexican spring wheat flour (cv. Tacupeto F2001) were isolated, characterized and gelled and the gel rheological properties and microstructure were investigated. These WEAX presented an arabinose to xylose ratio of 0.66, a ferulic acid and diferulic acid content of 0.526 and 0.036 µg/mg WEAX, respectively and a Fourier Transform Infra-Red (FT-IR) spectrum typical of arabinoxylans. The intrinsic viscosity and viscosimetric molecular weight values for WEAX were 3.5 dL/g and 504 kDa, respectively. WEAX solution at 2% (w/v) formed gels induced by a laccase as cross-linking agent. Cured WEAX gels registered storage (G’) and loss (G’’) modulus values of 31 and 5 Pa, respectively and a diferulic acid content of 0.12 µg/mg WEAX, only traces of triferulic acid were detected. Scanning electron microscopy analysis of the lyophilized WEAX gels showed that this material resembles that of an imperfect honeycomb.

Due to their porous structure, aqueous environment and dietary fiber nature arabinoxylan (AX) gels could have potential applications for colon-specific therapeutic molecule delivery. In addition, prebiotic and health related effects of AX have been previously demonstrated. It has been also reported that cross-linked AX can be degraded by bacteria from the intestinal microbiota. However, AX gels have not been abundantly studied as carrier systems and there is no information available concerning their capability to entrap cells. In this regard, probiotic bacteria such as Bifidobacterium longum have been the focus of intense research activity lately. The objective of this research was to investigate the entrapment of probiotic B. longum in AX gels. AX solution at 2% (w/v) containing B. longum (1 × 10⁷ CFU/cm) formed gels induced by laccase as cross-linking agent. The entrapment of B. longum decreased gel elasticity from 31 to 23 Pa, probably by affecting the physical interactions taking place between WEAX chains. Images of AX gels containing B. longum viewed under a scanning electron microscope show the gel network with the bacterial cells entrapped inside. The microstructure of these gels resembles that of an imperfect honeycomb. The results suggest that AX gels can be potential candidates for the entrapment of probiotics.

Vibrio parahaemolyticus is a pathogenic bacterium that threatens food safety by infecting humans and marine organisms. Among its virulence factors, lecithin-dependent hemolysin (vpLDH) has been identified as a promising target for attenuating its pathogenicity. This study explores the inhibitory mechanisms of three natural flavonoids—quercetin, morin, and EGCG—on LDH using enzyme kinetics, fluorescence quenching, and molecular dynamics simulations. The flavonoids quercetin, morin, and EGCG inhibited vpLDH phospholipase A2 activity via a competitive mechanism with inhibition constants of 17.1, 17.27, and 24.24 µM, respectively. Fluorescence quenching experiments confirmed that the evaluated flavonoids formed a stable, non-fluorescent complex (1:1 stoichiometry) with vpLDH. Also, via Stern–Volmer plots, the dissociation constant was calculated (Kd); quercetin showed the highest affinity, followed by morin and EGCG. Molecular dynamics simulations revealed that all evaluated ligands bind to the vpLDH active site vicinity with oscillations < 1.7 nm (100 ns), indicating that both the flavonoids and substrate vpLDH complexes are stable. These findings demonstrate that quercetin, morin, and EGCG are stable competitive inhibitors, highlighting their potential as natural anti-virulence agents against V. parahaemolyticus.