Antibacterial Properties of Coaxial Spinning Membrane of Methyl ferulate/zein and Its Preservation Effect on Sea Bass

Antioxidant, antibacterial, and molecular docking of methyl ferulate and oleic acid produced by Aspergillus pseudodeflectus AUMC 15761 utilizing wheat bran

Secondary metabolites (SMs) are the primary source of therapeutics and lead chemicals in medicine. They have been especially important in the creation of effective cures for conditions such as cancer, malaria, bacterial and fungal infections, neurological and cardiovascular problems, and autoimmune illnesses. In the present study, Aspergillus pseudodeflectus AUMC 15761 was demonstrated to use wheat bran in solid state fermentation (SSF) at optimum conditions (pH 7.0 at 30 °C after 10 days of incubation and using sodium nitrate as a nitrogen source) to produce methyl ferulate and oleic acid with significant antioxidant and antibacterial properties. Gas chromatography-mass spectrometry (GC-MS) analysis of the crude methanol extract revealed eleven peaks that indicated the most common chemical components. Purification of methyl ferulate and oleic acid was carried out by column chromatography, and both compounds were identified by in-depth spectroscopic analysis, including 1D and 2D NMR and HR-ESI-MS. DPPH activity increased as the sample concentration increased. IC50 values of both compounds obtained were 73.213 ± 11.20 and 104.178 ± 9.53 µM, respectively. Also, the MIC value for methyl ferulate against Bacillus subtilis and Staphylococcus aureus was 0.31 mg/mL, while the corresponding MIC values for oleic acid were 1.25 mg/mL and 0.62 mg/mL for both bacterial strains, respectively. Molecular modeling calculations were carried out to reveal the binding mode of methyl ferulate and oleic acid within the binding site of the crucial proteins of Staphylococcus aureus. The docking results were found to be well correlated with the experimental data.

Novel Ag-coated nanofibers prepared by electrospraying as a SERS platform for ultrasensitive and selective detection of nitrite in food

Nitrite is commonly used as a preservative and color fixative in the meat industry. However, the risk of it transforming into N-nitrosamine restricts its intake. Herein, a novel sensitive Ag-coated nanofiber surface-enhanced Raman scattering (SERS) platform was developed for rapid nitrite detection. The electrospraying technique was firstly used to assemble Ag nanoparticles (NPs) on the nanofibers to obtaine SERS platform. The homogeneity and long-term stability of the SERS platform were evaluated. The limit of detection (LOD) of the SERS platform was estimated to be 2.216 × 10^-12 mol/L, corresponding to 15.29 ng·L^-1 and good linearity was shown between the relative SERS intensity and nitrite concentration range of 10-1 to 10^-4 mol/L. The Ag-coated nanofiber SERS platform was utilized to assay-five common nitrite foods, and the results provided valid evidence for the compatibility of SERS platform in quantitative nitrite detection.

Influence of the Maillard Reaction on Properties of Air-Assisted Electrospun Gelatin/Zein/Glucose Nanofibers

To develop biodegradable, sustainable, and environment-friendly functional food-packaging materials, gelatin/zein/glucose nanofibers were fabricated through air-assisted electrospinning and then crosslinked by the Maillard reaction under mild conditions (60 °C and 50% relative humidity) in this study. Compared to traditional electrospinning, air-assisted electrospinning increased the yield of nanofibers by 10 times, and the average diameter from 263 nm to 664 nm, while the airflow facilitated uniform and smooth nanofiber formation. During the Maillard reaction in 0-5 days, the gelatin/zein/glucose showed no morphology change. Fourier transform infrared spectra analysis indicated that gelatin interacted with zein through hydrogen bonding and the occurrence of the Maillard reaction among the protein and glucose molecules. After four days of Maillard reaction, the nanofibers presented higher thermal stability, the most hydrophobic surface (water contact angle: 133.6°), and stiffer network structure (elastic modulus of 38.63 MPa, tensile strength of 0.85 MPa). Overall, Maillard-reaction-crosslinked gelatin/zein/glucose nanofibers showed favorable physical properties, which suggests their potential for application in food-active packaging.

Electrospinning as a Promising Process to Preserve the Quality and Safety of Meat and Meat Products

Fresh and processed meat products are staple foods worldwide. However, these products are considered perishable foods and their deterioration depends partly on the inner and external properties of meat. Beyond conventional meat preservation approaches, electrospinning has emerged as a novel effective alternative to develop active and intelligent packaging. Thus, this review aims to discuss the advantages and shortcomings of electrospinning application for quality and safety preservation of meat and processed meat products. Electrospun fibres are very versatile, and their features can be modulated to deliver functional properties such as antioxidant and antimicrobial effects resulting in shelf-life extension and in some cases product quality improvement. Compared to conventional processes, electrospun fibres provide advantages such as casting and coating in the fabrication of active systems, indicators, and sensors. The approaches for improving, stabilizing, and controlling the release of active compounds and highly sensitive, rapid, and reliable responsiveness, under changes in real-time are still challenging for innovative packaging development. Despite their advantages, the active and intelligent electrospun fibres for meat packaging are still restricted to research and not yet widely used for commercial products. Industrial validation of lab-scale achievements of electrospinning might boost their commercialisation. Safety must be addressed by evaluating the impact of electrospun fibres migration from package to foods on human health. This information will contribute into filling knowledge gaps and sustain clear regulations.