The increasing demand for sustainable, high-performance materials in food packaging highlights the need to understand how bio-based additives and metallic nanofillers influence the stability and degradation behavior of polylactic acid (PLA) composites under food-contact conditions. In this study, PLA-based composites containing grape pomace and silver or copper nanoparticles were developed and evaluated in terms of physico-chemical stability, thermal behavior, and degradation mechanisms. Two commercial PLA grades (PLA1 and PLA2) were blended with Proviplast 2624 plasticizer and doped with grape pomace powder or Ag-PEG/Cu-PEG nanofillers. Nine composite formulations were prepared by melt processing and immersed for six months in three food simulants (10% ethanol, 3% acetic acid, and 20% ethanol) to investigate mass variation, Vickers hardness, surface morphology, and chemical and thermal changes. Scanning electron microscopy (SEM), electron paramagnetic resonance (EPR), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) were used to correlate morphological, chemical, and structural modifications occurring during exposure. The results showed that both composite formulation and simulant type significantly affected the structural, mechanical, and degradation behavior of the materials. Grape pomace-reinforced samples exhibited increased Vickers hardness after immersion, particularly in ethanolic media, attributed to the rigid structure of the filler and its stabilizing effect on the polymer matrix. Composites containing Ag-PEG and Cu-PEG nanofillers showed improved nanoparticle dispersion and partial stabilization of the PLA matrix, with enhanced performance at 8% nanoparticle loading. However, prolonged exposure to simulants resulted in polymer degradation characterized by mass variation, surface damage, and free-radical formation detectable by EPR. FTIR and DSC analyses indicated structural and thermal changes consistent with hydrolysis-induced chain scission, while acetic acid proved to be the most aggressive medium, accelerating hydrolytic degradation and structural fragmentation.

Correction for ‘Aging and degradation behaviour of poly(lactic acid) composites in alcoholic and acidic food simulants’ by Andrei Moldovan et al. , RSC Adv. , 2026, 16 , 20946–20959, https://doi.org/10.1039/D6RA01374K.

A plasticized polylactic acid (PLA) composite incorporating zinc oxide (ZnO) was synthesized via melt mixing and hot pressing. The physicochemical and preliminary microbiological properties of the composite were systematically evaluated. ZnO powder, produced through precipitation and calcination, was characterized using dynamic light scattering and nitrogen sorption analysis. The PLA composite, comprising PLA, Proviplast 2624, Span 60, and ZnO, was subjected to tensile and flexural testing, oxygen and water vapor barrier measurements, water uptake analysis, contact angle assessment, and Atenuated Total Reflectance – Fourier Transform Infrared spectroscopy (ATR-FTIR). The ZnO powder exhibited a broad, aggregate-dominated particle-size distribution and a moderate specific surface area. The composite displayed reduced stiffness and strength relative to neat PLA, indicating effective plasticization. Preliminary microbiological assays indicated decreased recovery of the tested microorganisms under the specified conditions.

Biodegradable polymeric materials with antimicrobial functionality are increasingly explored as sustainable alternatives for food packaging. This study developed multifunctional PLA-based composite films containing controlled concentrations of active agents and evaluated their structural, mechanical, thermal, and antimicrobial properties. Five formulations were prepared: a reference PLA/glycerol diacetate blend (85/15 wt. %) and four composites with 0.5 wt. % functional fillers—grape pomace, silver–graphene oxide (GO-Ag), titanium dioxide–graphene oxide (GO-TiO2), or graphene oxide (GO)—with PLA adjusted to 84.5 wt. %. The films were characterized for antimicrobial activity, tensile strength, hardness (Vickers test), morphology (SEM), and thermal behavior (DSC). Mechanical testing revealed statistically significant differences (p < 0.05), with Vickers hardness increasing from neat PLA (13.77) to 0.5% grape pomace (16.30) and nanofiller composites (GO–Ag 18.59, GO 19.56, GO–TiO2 22.7), demonstrating enhanced stiffness and efficient load transfer. Incorporation of Ag and TiO2 shifted endothermic transitions to higher temperatures, particularly in PLA-GT (~140 °C), indicating improved thermal stability, while neat PLA and PLA-GP showed multiple or intermediate transitions (86–92 °C). Antibacterial performance was strongly influenced by composition and surface characteristics, with PLA-GA, PLA-GT, and PLA-GO showing the greatest efficacy. These findings demonstrate that bioactive and nanostructured fillers can effectively enhance the mechanical, thermal, and antimicrobial properties of PLA, highlighting their potential for sustainable, functional food packaging applications.

To support a sustainable economy, the development of advanced and environmentally friendly food packaging systems is essential. This study presents innovative biodegradable composites based on polylactic acid (PLA), incorporating grape pomace and copper (Cu) nanoparticles as functional fillers to improve packaging performance. The composites exhibited rapid swelling when exposed to liquids. Grape pomace promoted a stable swelling behavior, maintaining a rate of 1.2

The use of waste wine byproducts in packaging manufacture can offer an alternative to plastic pollution. Thus, grape pomace possesses properties that could improve the performance of plastic materials. In this work, the conditioning of grape pomace was studied for the purpose of adding PLA films. Resveratrol was extracted from grape pomace, which was then incorporated into PLA films to enhance their performance. The obtained biopolymers were characterized by determining the mechanical, thermal, and structural properties. The tensile strength of the composites has similar values for the composite with pomace and those with resveratrol, and a similar flexibility of the analyzed samples. The thermal stability of the pomace waste and the composites to which pomace and resveratrol were added was high. DSC tests of PLA-based composites revealed two endothermic peaks at temperatures above 120 °C, probably caused by the melting of amorphous structures. Surface examination indicated a relatively uniform distribution of pomace or resveratrol particles in the polymer matrix, and surface roughness parameters calculated by atomic force microscopy indicated a low to moderate level of roughness, with higher values for pomace-containing films than for resveratrol-based ones, highlighting the more hydrophilic nature of pomace-containing films compared to resveratrol-based ones.

Composites based on polylactic acid (PLA) and copper for food packaging applications were obtained. Copper clusters were synthesized in polyethylene glycols 400 and 600, respectively, using ascorbic acid as a reducing agent, by reactive milling. Copper clusters were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FT-IR), and Ultraviolet-Visible (UV-VIS) spectroscopy. Copper/PLA composites containing Proviplast as plasticizer were characterized by FT-IR spectroscopy, mechanical tests, Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), absorption of the saline solution, contact angle, and antibacterial properties. It was observed that the concentration of Copper/PEG influenced the investigated properties. The mechanical properties of the samples decreased with the increasing of Copper/PEG concentration. We recorded the phase transformation temperatures and identified the exothermic or endothermic processes. The lowest absorption values were recorded in the case of the sample containing 1% Cu. The contact angle decreases with the increase in the concentration of the PEG 600-Cu mixture in the recipes. The increase in the content of Cu clusters favors the decrease in the temperature, taking place 15% wt mass losses. The obtained composites showed antibacterial properties for all tested strains. These materials could be used as alternative materials for obtaining biodegradable food packaging.

The present study is focused on polylactic acid (PLA) blending with bio nanoadditives, such as Tonsil® (clay) and Aerosil®, to obtain nanocomposites for a new generation of food packaging. The basic composition was enhanced using Sorbitan oleate (E494) and Proviplast as plasticizers, increasing the composite samples' stability and their mechanical strength. Four mixtures were prepared: S1 with Tonsil®; S2 with Aerosil®; S3 with Aerosil® + Proviplast; and S4 with Sabosorb. They were complexly characterized by FT-IR spectroscopy, differential scanning calorimetry, mechanical tests on different temperatures, and absorption of the saline solution. FTIR shows a proper embedding of the filler component into the polymer matrix and DSC presents a good stability at the living body temperature for all prepared samples. Micro and nanostructural aspects were evidenced by SEM and AFM microscopy, revealing that S3 has the most compact and uniform filler distribution and S4 has the most irregular one. Thus, S3 evidenced the best diametral tensile strength and S4 evidenced the weakest values. All samples present the best bending strength at 18 °C and fair values at 4 °C, with the best values being obtained for the S1 sample and the worst for S4. The lack of mechanical strength of the S4 sample is compensated by its best resistance at liquid penetration, while S1 is more affected by the liquid infiltrations. Finally, results show that PLA composites are suitable for biodegradable and disposable food packages, and the desired properties could be achieved by proper adjustment of the filler proportions.