The objective of present work was to construct antibacterial [2-(methacryloyloxy) ethyl] trimethylammonium chloride functionalized reduced graphene oxide/poly(ethylene-co-vinyl alcohol) (MTAC-rGO/EVOH) multilayer barrier films by using layer-by-layer assembly under a parallel electric field. Besides barrier and mechanical properties, the antibacterial activities of the film and cytotoxicity of MTAC-rGO nanosheets were extensively investigated. The functionalization of rGO was achieved by grafting MTAC onto a graphene framework through C (sp)-C bonds. The assembly of MTAC-rGO on the EVOH matrix not only significantly improved film mechanical strength, but also endowed the targeting film with outstanding moisture barrier even under a relative humidity of 99% (e.g., 0.019 g m s atm for (MTAC-rGO/EVOH)) besides good oxygen barrier (e.g., 0.07 cm m d atm for (MTAC-rGO/EVOH)). Among the testing films, MTAC-rGO/EVOH film had the best antibacterial activity, and the activity against S. aureus was better than E. coli. Meanwhile, the cytotoxicity of MTAC-rGO nanosheets was very low. Results suggest that MTAC-rGO/EVOH film may have great potential in food active packaging.

The present work aimed to develop a porous‐gelatinized corn starch and evaluate its adsorption of grape seed proanthocyanidins (GSPs). The starches were fabricated by subjecting a porous starch (enzymolysis with α‐amylase and amyloglucosidase) to moderate gelatinization at 65°C for 3 h. The resulting morphology, structure, and properties strongly depended on the order of the enzymolysis and gelatinization steps. The porous‐gelatinized starch was mesoporous. During gelatinization, the pores in the enzymolysis starches shrank and some disappeared. Neither enzymolysis nor gelatinization changed the basic chemical structures of the starch. However, the crystallinity was increased by enzymolysis and decreased by gelatinization. Furthermore, the reduction in crystallinity decreased the enthalpy change (ΔH) and increased the peak temperature (Tp). The limited swelling upon gelatinization favored the diffusion of water molecules into the starch matrix and increased the water absorbability of the starches. A pseudo‐first‐order kinetic model accurately described the adsorption of porous‐gelatinized starch toward GSPs (R2 > 0.995). The porous‐gelatinized starch showed the best adsorption capability (qe = 18.890 ± 0.084 mg/g) and a relatively low desorption tendency (49%) toward GSPs. Thus, this starch may be used as an effective adsorbent in order to improve the utilization efficiency of GSPs and maintain their antioxidant activity.

The proanthocyanidins encapsulated in zein (zein-PA) fibers was via electrospinning technique. The kinetics and antioxidant capacity of PA from zein fibers was investigated by cyclic voltammetry. Circular dichroism was used to investigate the secondary structure change of zein and its influence on the shape of fibers. The addition of PA caused a significant increase in viscosity and made fibers wider. These hydrogen bonds between zein and PA molecules would favor the α-helix change and decrease the β-folds of zein in electrospinning solutions, leading to a round-shaped tendency of fibers and enhancing the thermal properties slightly. Zein-PA fibers showed high encapsulation efficiency close to 100%, and the encapsulated PA retained its antioxidant capacity in fibers. Zein-PA fibers showed a good controlled release toward PA, and the predominant release of PA from fibers was Fickian diffusion, which could be well described by first-order model and Hixson-Crowell model.

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