Volatile active ingredients in biopolymer nanofibers are prone to burst and uncontrolled release. In this study, we used electrospinning and crosslinking to design a new sustained-release active packaging containing zein and eugenol (EU). Vapor-phase glutaraldehyde (GTA) was used as the crosslinker. Characterization of the crosslinked zein nanofibers was conducted via scanning electron microscopy (SEM), mechanical properties, water resistance, and Fourier transform infrared (FT-IR) spectroscopy. It was observed that crosslinked zein nanofibers did not lose their fiber shape, but the diameter of the fibers increased. By increasing the crosslink time, the mechanical properties and water resistance of the crosslinked zein nanofibers were greatly improved. The FT-IR results demonstrated the formation of chemical bonds between free amino groups in zein molecules and aldehyde groups in GTA molecules. EU was added to the zein nanofibers, and the corresponding release behavior in PBS was investigated using the dialysis membrane method. With an increase in crosslink time, the release rate of EU from crosslinked zein nanofibers decreased. This study demonstrates the potential of crosslinking by GTA vapors on the controlled release of the zein encapsulation structure containing EU. Such sustainable-release nanofibers have promising potential for the design of fortified foods or as active and smart food packaging.

In this work, a novel reinforcing filler, millet gliadin (MG), was used for the improvement of the mechanical properties of zein nanofibers. The structural and physicochemical properties of MG were compared with those of zein, and the influence of MG on the morphology, physical properties, and molecular structure of zein nanofibers was investigated. The results indicated that MG has an obviously smaller weight-average molecular weight (7623) in comparison to zein (13,330). Transmission electron microscopy showed that zein molecules more easily form aggregates with larger diameters than MG molecules in acetic acid. At a concentration of 30% (w/v), MG exhibited a significantly higher viscosity (0.66 ± 0.03 Pa·s) than zein (0.32 ± 0.01 Pa·s), indicating the stronger interactions of MG molecules. With the incorporation of MG, the tensile strength was significantly increased to 49.32 MPa (ZM-1/2), which is 2.08 times and 4.45 times higher than that of pure zein nanofibers (ZM-1/0) and MG nanofibers (ZM-0/1-1), respectively. Moreover, zein/MG composite nanofibers exhibited improved water stability. Fourier transform infrared spectra showed evidence of the hydrogen bonding interaction between zein and MG. Therefore, MG is a good candidate for use as a natural reinforcing filler in electrospun nanofibers made of biopolymers.

The poor rehydration capacity of micellar casein (MC) powder due to the tightly cross-linked structure formed by colloidal calcium phosphate (CCP) limits its potential applications. This study aimed to improve the rehydration properties of MC powder by electrodialysis (ED) treatment. After being treated by ED for 0, 10, 30, 60, and 90 min, the casein micelle powder exhibited a reduction in calcium content (25.55 ± 0.08 g/kg to 17.47 ± 0.05 g/kg) with prolonged treatment, corresponding to the progressive dissociation of CCP bridges. Furthermore, the ED treatment significantly increased the solubility of casein micelle powder. Interestingly, after 60 min, the solubility of ED-treated micellar casein plateaued at approximately 80% within 30 min, likely due to modification on protein structure. Therefore, these results indicate that the structure of micellar casein can be modified through ED treatment, leading to improved rehydration properties.

Pork jerky is vulnerable to quality deterioration during distribution, particularly under hot and humid conditions. This study investigated the deterioration pattern and associated mechanisms for vacuum-packaged pork jerky sealed in aluminum foil pouches during accelerated high-temperature and high-humidity storage (65 °C and relative humidity of 85%). The sensory quality, physicochemical properties, oxidation-related changes, non-enzymatic browning, and protein digestibility were evaluated, and multivariate analyses were performed to characterize the deterioration process. Sensory acceptability declined markedly, and the rejection rate reached 50% on day 14, indicating the shelf-life endpoint under the test conditions. Deterioration in quality was mainly characterized by color darkening, texture hardening, water redistribution, and microstructural disruption. Lipid oxidation, protein oxidation, myoglobin oxidation, and non-enzymatic browning progressively intensified during storage and were associated with the observed color deterioration and sensory decline. Microbiological indicators remained below the detection limit throughout storage, suggesting that quality deterioration was primarily associated with chemical rather than microbial changes. Multivariate analyses further suggested that lipid oxidation, protein oxidation, myoglobin oxidation, and non-enzymatic browning were key processes potentially associated with quality loss. These findings provide a basis for shelf-life evaluation and quality control for pork jerky under extreme storage conditions.

Electrospun zein nanofibers are promising bio-based materials, but producing uniform ultrafine fibers with desirable performance remains challenging. This study examined the effects of process variables and three surfactants on zein fiber formation, diameter, and material properties. Zein solutions (30–40%, w/v) were prepared in glacial acetic acid, and 2% (w/w, based on zein) triethyl benzyl ammonium chloride (TEBAC), sodium dodecyl sulfate (SDS), or span-80 was incorporated into the 30% zein solution. Zein concentration and feed rate yielded fiber diameters of 208.22–1001.90 nm. Surfactants reduced surface tension and increased conductivity, promoting jet stretching and generating uniform fibers with diameters near 100 nm. SDS produced the smallest fibers (98.92 ± 15.20 nm). TEBAC increased tensile strength from 11.08 to 63.26 MPa and improved dimensional retention in water, whereas SDS and span-80 increased elongation at break but reduced strength and stiffness. All surfactants increased wettability and altered intermolecular interactions and secondary structure of zein, although they reduced thermal stability. Overall, surfactants acted as both electrospinning aids and structure-directing modifiers, with TEBAC providing the best balance of fineness, strength, and aqueous stability. These ultrafine, robust, and water-stable nanofibers are promising as functional coating layers for high-moisture food packaging and as carriers for antioxidants or antimicrobial agents.