Poly(butylene adipate-co-terephthalate) (PBAT) and graphene oxide (GO) nanocomposite films were prepared by extrusion to evaluate their potential as films for food packaging. The films were prepared with contents of 0.05, 0.1, and 0.25% in mass of GO by solid-solid deposition methodology. It was verified that GO did not modify the hydrophobicity and crystallinity degree of PBAT. The reduction of molecular weight due to GO incorporation was verified, and it could be the main reason for the observed decrease in tensile strength and increase in elongation. The nanofiller permitted ultraviolet blocking, thermal stability, and oxygen barrier improvements without compromising film visibility. Compared to the neat PBAT film, the oxygen permeability coefficient was reduced by 13.6% for PBAT/GO0.25. The elongation and tenacity were also improved by 90% and 33%, respectively, for the highest concentration of GO (0.25%). Besides, GO at 0.25% accelerated the mineralization rate of PBAT in soil, probably due to the lower molecular weight of nanocomposites in relation to the neat polymer. The preliminary information obtained in this work indicates that the level of PBAT hydrolytic degradation during the extrusion process was not high enough to avoid its application in food packaging because the obtained thermal, mechanical, and ultraviolet (UV) barriers still indicate an exciting balance of properties for this purpose, which can even be improved with future research.

The global food demand is increasing with the world population, burdening agriculture with unprecedented challenges. Agricultural techniques that ushered in the green revolution are now unsustainable, owing to population growth and climate change. The agri-tech revolution that promises a robust, efficient, and sustainable agricultural system while enhancing food security is expected to be greatly aided by advancements in nanotechnology, which have been reviewed here. Nanofertilizers and nanoinsecticides can benefit agricultural practices economically without major environment impact. Owing to their unique size and features, nanoagrochemicals provide enhanced delivery of active ingredients and increased bioavailability, and posing lesser environment hazard. Nano-agrochemicals should be improved for increased efficiency in the future. In this context, nanocomposites have drawn considerable interest with regard to food security. Nanocomposites can overcome the drawbacks of chemical fertilizers and improve plant output and nutrient bioavailability. Similarly, metallic and polymeric nanoparticles (NPs) can potentially improve sustainable agriculture via better plant development, increased nutrient uptake, and soil healing. Hence, they can be employed as nanofertilizers, nanopesticides, and nanoherbicides. Nanotechnology is also being used to enhance crop production via genetic modification of traits for efficient use of soil nutrients and higher yields. Furthermore, NPs can help plants overcome salinity stress-induced oxidative damage. We also review the fate of NPs in the soil system, plants, animals, and humans, highlight the shortcomings of previous research, and offer suggestions for toxicity studies that would aid regulatory bodies and benefit the agrochemical sector, consequently promoting efficient and sustainable use of nano-agrochemicals.

The aim of this work was to evaluate the influence of halloysite clay nanoparticles - unmodified (Hal) and organically modified (mHal) - and oregano essential oil (OEO), used as an antimicrobial agent in active packaging, on the biodegradation behavior of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) films. Five samples were prepared by melt mixing using 3 wt% clay, and 8 wt% and 10.4 wt% OEO. PHBV compositions containing OEO presented the highest rate of biodegradation, achieving 46% of mass loss after aging for 12 weeks in simulated soil. The addition of clay nanoparticles reduced the polymer's biodegradation to 32%. The compositions containing OEO showed a rough and layered surface with visible cracks, indicating degradation occurring through layer-by-layer erosion from the surface. This degradation was confirmed by the chemical changes on the surface of all samples, with a slight decrease in molar masses. The composition containing 8 wt% OEO presented an increase in the crystallization degree as a result of the preferential consumption of amorphous phase, whereas for the compositions containing clay nanoparticles, both crystalline and amorphous regions were degraded at similar rates. Therefore, the combination of additives allows the biodegradation process of PHBV to be controlled for use in the production of active packaging.

In the pursuit of enhancing food packaging, nanotechnology, particularly green silver nanoparticles (G-AgNPs), have gained prominence for its remarkable antimicrobial properties with high potential for food shelf-life extension. Our study aims to develop corn starch-based coating materials reinforced with G-AgNPs. The mechanical properties were examined using a uniaxial tensile tester, revealing that starch coated with the highest G-AgNPs concentration (12.75 ppm) exhibited UTS of 87.6 MPa compared to 48.48 MPa of control paper, a significant (p < 0.02) 65% increase. The assessment of the WVP showcased a statistical reduction in permeability by up to 8% with the incorporation of the hydrophobic layer. Furthermore, antibacterial properties were assessed following ISO 22196:2011, demonstrating a strong and concentration-dependent activity of G-AgNPs against E. coli. All samples successfully disintegrated in both simulated environments (soil and seawater), including samples presenting G-AgNPs. In the food trial analysis, the presence of starch and G-AgNPs significantly reduced weight loss after 6 days, with cherry tomatoes decreasing by 8.59% and green grapes by 6.77% only. The results of this study contribute to the advancement of environmentally friendly packaging materials, aligning with the UN sustainable development goals of reducing food waste and promoting sustainability.

Biofilm and bionanocomposite films were synthesized from polyvinylpyrrolidone (PVP), chitosan (CS), citric acid (CA), and zinc oxide-nanoparticles (ZnO-NPs). Effects of gamma-irradiation dose and ZnO-NPs concentrations; 0, 0.1, 0.3, 0.6, 0.9, 1.2, and 1.5 (wt./wt.)% were studied. Biofilms and bionanocomposite films were characterized by Fourier transform infrared, Raman spectroscopy, transmission electron microscopy, thermal gravimetric analysis, X-rays diffraction, energy dispersive X-ray, and mechanical properties to identify structure of biofilm and bionanocomposite films. Swelling (g/g)% and gelation (g/g)% of biofilms were carried out at diverse compositions of PVP to CS of (1/1), (1/2), and (2/1) (v/v). Swelling (g/g)% results of (1/1), (1/2), and (2/1) (v/v) were 116, 110, and 126, respectively. Values of highest and lowest gelation (g/g)% of (1/2) and (2/1) (v/v) are 98.0 +/- 1.8 and 85.0 +/- 2.6, respectively at 30 kGy. Water vapor transmission rate was studied for films and exposed 3450 +/- 4.1 and 185.8 +/- 1.2 (kg/m(2).day) for open bottle and (PVP/CS/PCA)/(ZnO-NPs-1.5), respectively. Values of water solubility (g/g)% were investigated and found 30.21 +/- 1.3 and 15.4 +/- 2.5 for (PVP/CS/PCA)/(ZnO-NPs-0) and (PVP/CS/PCA)/(ZnO-NPs-1.5), accordingly. Bionanocomposite films displayed a broad-spectrum antimicrobial activity against Gram-negative bacteria and Gram-positive bacteria. (PVP/CS/PCA)/(ZnO-NPs-0.1) showed lowest inhibition zone; 4 +/- 0.2, 9 +/- 0.5, 19 +/- 0.1, and 8 +/- 0.3 (mm) compared with (PVP/CS/PCA)/(ZnO-NPs-1.5) of highest inhibition zone; 16 +/- 0.5, 28 +/- 0.2, 33 +/- 0.6, and 18 +/- 0.3 (mm) for Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus, respectively. Antimicrobial activity increased with increasing ZnO-NPs concentrations. Biodegradation of biofilms and bionanocomposite films were examined under soil from 0 to120 days. Results of weight loss (g/g)% at 120 days of (PVP/CS/PCA)/(ZnO-NPs-0) and (PVP/CS/PCA)/(ZnO-NPs-1.5) are 72 +/- 4.5 and 47.5 +/- 3.8, respectively. Bionanocomposite films were used in food preservation of fresh cherry tomatoes for 30 days and showed goodness. Therefore, these results suggest that the possibility of using bionanocomposite films in food-packaging applications.