Edible coatings and films (ECF) are employed as matrixes for incorporating antimicrobial nanoparticles (NPs), and then they are applied on the fruits and vegetables to prolong shelf life and enhance storage quality. This paper provides a comprehensive review on the preparation, antimicrobial properties and mechanisms, surface and physical qualities of ECF containing antimicrobial NPs, and its efficient application to vegetables and fruits as well. Following an introduction on the properties of the main edible coating materials, the preparation technologies of ECF with NPs are summarized. The antimicrobial activity of ECF with NPs against the tested microorganism was observed by many researchers. This might be mainly due to the electrostatic interaction between the cationic polymer or free metal ions and the charged cell membrane, the photocatalytic reaction of NPs, the detachment of free metal ion, and partly due to the antimicrobial activity of edible materials. Moreover, their physical, mechanical and releasing properties are discussed in detail, which might be influenced by the concentration of NPs. The preservation potential on the quality of fruits and vegetables indicates that various ECF with NPs might be used as the ideal materials for food application. Following the introduction on these characteristics, an attempt is made to predict future trends in this field.

In this investigation, the effect of different concentrations of titanium dioxide (TiO₂) nanoparticles (NPs) on the structure and antimicrobial activity of chitosan-based coating films was examined. Analysis using scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed that the modified TiO₂ NPs were successfully dispersed into the chitosan matrix, and that the roughness of the chitosan-TiO₂ nanocomposites were significantly reduced. Moreover, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses indicated that the chitosan interacted with TiO₂ NPs and possessed good compatibility, while a thermogravimetric analysis (TGA) of the thermal properties showed that the chitosan-TiO₂ nanocomposites with 0.05% TiO₂ NPs concentration had the best thermal stability. The chitosan-TiO₂ nanocomposite exhibited an inhibitory effect on the growth of Escherichia coli and Staphylococcus aureus. This antimicrobial activity of the chitosan-TiO₂ nanocomposites had an inhibition zone ranging from 9.86 ± 0.90 to 13.55 ± 0.35 (mm). These results, therefore, indicate that chitosan-based coating films incorporated with TiO₂ NPs might become a potential packaging system for prolonging the shelf-life of fruits and vegetables.

The green synthesis of silver nanoparticles (AgNPs) from biological waste, as well as their excellent antibacterial properties, is currently attracting significant research attention. This study synthesized AgNPs from different mango peel extract concentrations while investigating their characteristics and antibacterial properties. The results showed that the AgNPs were irregular with rod-like, spherical shapes and were detected in a range of 25 nm to 75 nm. The AgNPs displayed antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), showing a more significant impact when synthesized with 0.20 g/mL of mango peel extract. Therefore, the antibacterial effect of different diluted AgNP concentrations on the growth kinetic curves of E. coli and S. aureus after synthesis with 0.20 g/mL mango peel extract was analyzed. The results indicated that the AgNP antibacterial activity was higher against S. aureus than against E. coli, while the AgNP IC50 in these two strains was approximately 1.557 mg/mL and 2.335 mg/L, respectively. This research provides new insights regarding the use of postharvest mango byproducts and the potential for developing additional AgNP composite antibacterial materials for fruit and vegetable preservation.

In this study, the aroma compounds of Huantai tartary buckwheat tea (TBH), three laboratory-produced scented tartary buckwheat teas, as well as the antioxidant activity of tea infusion was investigated. In total, 103 aroma components were isolated and identified from all samples. Tartary buckwheat rose tea (TBR) contained 57 aroma components and tartary buckwheat jasmine tea (TBJ) had 53, both of which were higher than those in others. In addition, the total flavonoid content (TFC) and the total phenolic content (TPC) of scented tartary buckwheat tea were much higher than those of TBH. After the tartary buckwheat tea (TBT) was soaked in hot water twice, the antioxidant activity of all samples decreased, and the antioxidant activity of TBR and TBJ infusions was more stable than those of others. Further, the antioxidant activity of the first tea infusion (FTI) of the TBT was higher than that of the second tea infusion (STI). Overall, considering the diverse aroma compounds of scented tartary buckwheat tea and higher antioxidant activity of tea infusions, the combination of scented tea and tartary buckwheat is a feasible approach to develop tartary buckwheat scented tea.