Qin Li

In this study, composite nanofibrous membranes composed of poly(vinyl alcohol) (PVA), gelatin, and zein loaded with different contents of dihydromyricetin (DMY) were fabricated via electroblowing spinning (EBS). The effects of DMY content on the microstructure, physicochemical properties, mechanical strength, and functional performance of the membranes were evaluated. Scanning electron microscopy (SEM) analysis showed that the average fiber diameter increased from 174 ± 29 nm to 221 ± 35 nm with increasing DMY content, followed by a slight decrease at higher loading levels, indicating that DMY incorporation influences fiber morphology. Fourier transform infrared spectroscopy (FTIR) results suggested the presence of hydrogen bonding interactions between DMY and the polymer matrix. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) results indicated changes in the physical state of DMY within the nanofibrous system as the loading content increased. All samples exhibited a typical two-stage release behavior, and the highest cumulative release (nearly 55%) was observed at a DMY loading of 22.5%, while further increasing the loading reduced the release efficiency to approximately 45%. The release profiles were well described by a first-order kinetic model. The composite membranes exhibited improved surface hydrophilicity, appropriate water vapor permeability, antioxidant activity, and antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). This study demonstrates the successful fabrication of DMY-loaded PVA/gelatin/zein nanofibrous membranes and provides preliminary insights into their structure–property–function relationships, release behavior, antioxidant activity, and antibacterial activity against representative bacteria, although further application-oriented validation is still required.

Synthetic polymers are commonly incorporated into natural polymer nanofibers to enhance their overall performance. In this study, we investigated the effects of different poly(vinyl alcohol) (PVA) concentrations (0%, 2.5%, 5%, 7.5%, and 10% w/v) on the properties of gelatin/zein nanofibers. With increasing PVA concentration, fiber diameter significantly decreased from 976 ± 165 nm to 262 ± 60 nm, followed by a gradual increase to 396 ± 81 nm, indicating that PVA plays a crucial role in fiber diameter regulation. At higher concentrations (7.5% and 10% w/v), PVA became dominant, inducing protein aggregation and porous channel formation, which in turn increased the water vapor permeability of the composites. Rheological and mechanical analyses revealed that at these concentrations, the composites exhibited enhanced flexibility while maintaining network stability, demonstrating strong application potential. Furthermore, PVA incorporation induced a slight increase in the primary decomposition temperature (from 320.77 °C to 328.67 °C), indicating enhanced intermolecular compatibility and restricted segmental mobility within the protein–PVA network. Overall, these results establish a theoretical basis for tailoring fiber architecture and interfacial compatibility in natural–synthetic polymer composites. Further, the structural attributes of the resulting fibrous mats indicate their potential for food processing applications beyond conventional food packaging, including use as filtration media.

Recently, renewable biopolymers have gained growing attention as an alternative to petroleum-based materials in the packaging industry due to their eco-friendliness, biodegradability, and biocompatibility. This study introduces an innovative method for producing active films, which uses natural bacterial cellulose (BC) films as the matrix and incorporates (−)-Epigallocatechin-3-gallate (EGCG) through an immersion process. The incorporation of EGCG improves the barrier performance against oxygen and UV of the BC-based active films while preserving their tensile strength without compromising their opacity. More importantly, the active films exhibited significant antibacterial effects, with the efficacy increasing with the concentration of EGCG. Specifically, the diameters of the inhibition zones enlarged progressively against both S. aureus (from 13.88 to 16.25 mm, p < 0.05) and E. coli (from 12.38 to 14.13 mm). Correspondingly, the antibacterial rate of the active films increased from 61.4% to 80.61% (p < 0.05) against S. aureus and from 57.38% to 60.38% against E. coli. Additionally, the BC-based active films developed in this work exhibit excellent biodegradability, being capable of achieving complete biodegradation within 21 days of soil burial. This breakthrough exhibits considerable potential of BC-based active films as eco-friendly packaging materials, showing exceptional promise for sustainable active food packaging applications.

Lactobacillus fermentum (L. fermentum) was first evaluated as a potential advanced glycation end-product (AGE) formation inhibitor by establishing a bovine serum albumin (BSA) + glucose (glu) glycation model in the present study. The results showed that the highest inhibition rates of pentosidine and total fluorescent AGEs by L. fermentum were approximately 51.67% and 77.22%, respectively, which were higher than that of aminoguanidine (AG). Mechanistic analysis showed that L. fermentum could capture methylglyoxal and glyoxal, inhibit carbonyl and sulfhydryl oxidation, reduce the binding of glucose and amino groups, increase total phenolic content and antioxidant activity, and release intracellular substances to scavenge free radicals; these abilities were the basis of the antiglycation mechanism of L. fermentum. In addition, L. fermentum significantly prevented conformational changes in proteins during glycation, reduced protein cross-linking by 35.67%, and protected the intrinsic fluorophore. Therefore, the inhibition of L. fermentum on glycation mainly occurs through antioxidation, the capture of dicarbonyl compounds, and the protection of the BSA structure. These findings collectively suggest that Lactobacillus is an inhibitor of protein glycation and AGE formation and has the potential for nutraceutical applications.