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Non-biodegradable plastics have been extensively used for food packaging due to their outstanding properties that preserve food quality during transportation and shelf-life. The global awareness of plastic pollution has led to the development of environmentally friendly technologies for food packaging such as biodegradable polymers, edible films and coatings, and active or smart packaging. However, the petroleum-based polymers market seems not to be interested in setting back and current waste management strategies continue to be deficient in both technical and economic aspects. This work aimed to provide insights into the state-of-the-art technologies for food packaging based on the advances that have been made to improve the moisture, heat, and barrier properties of novel materials that could close the gap to conventional plastics in terms of performance and costs. This literature review takes a multidisciplinary approach, focusing on the required properties of food packaging and the potential impact on the physicochemical properties of food products. The aim is to identify gaps between current technologies and market demand that impede the alignment of the food packaging industry with global environmental policies. Several sustainable packaging options were identified, such as biopolymers like PLA or PBAT. However, most successful packaging solutions are made up of PVA, chitosan, gelatin, or films based on proteins. In both cases, the addition of essential oils, natural extracts, or nanoparticles to the packaging material has demonstrated its effectiveness in improving performance and ensuring food preservation over an extended period on the shelf. However, a significant research gap has been identified regarding the scaling up of packaging materials based on natural polymers, despite the technology appearing to be sufficiently advanced for practical implementation. Hence, it is necessary not only to optimize parameters to enhance functionality and mechanical properties but to demonstrate their feasibility for industrial production. Furthermore, it is essential to assess their environmental impact. It is important to provide evidence of the feasibility of real-world applications of the new materials developed, demonstrating their effectiveness under critical storage conditions for the preservation of different food groups.

Nowadays, poly(lactic acid) (PLA) is one of the most used biobased polymers with significant growth in the global market. Even though one of the main characteristics of PLA is its biodegradability, this process can generate environmental impact, soil use, and genotoxicity of residues. Additionally, PLA still has a considerably high cost, limiting its competitiveness with conventional oil-based thermoplastics. In this sense, this review discusses the reprocessing and recycling of PLA as an alternative to direct biodegradation to explore more economically viable end-of-life options (EoL). The PLA recycling methods are described, and mechanical recycling is highlighted due to its low environmental impact and common availability. The use of specific additives and their importance in maintaining acceptable PLA properties after reprocessing cycles are presented. The reprocessing and recycling effects on the molecular structure, rheological properties, and thermo-mechanical properties of PLA are shown and discussed. Weathering and abiotic factors are also included since they influence PLA recycling by generating previous degradation. In addition, the environmental impact of PLA recycling methods is presented and compared to other EoL options based on life cycle assessment (LCA).

The management of municipal solid waste (MSW) is a complex and expensive task. This is especially the case in developing countries, where waste generation rates are continuously increasing and where current MSW management strategies are focused on inadequate practices, such as landfilling and incineration, which result in numerous health and environmental problems. The anaerobic digestion (AD) of MSW has been implemented worldwide as a solution to decrease the amount of waste ending up in landfills. This process allows for the recovery of energy from the organic fraction of MSW (OFMSW) in the form of biogas, which is largely composed of methane. Therefore, the goal of the present study was to evaluate the biochemical methane potential (BMP) of the OFMSW generated within different socioeconomic strata of the Metropolitan Area of Guadalajara (MAG), Mexico. From a microscale perspective, the microbial communities within the experimental AD system were analyzed using high-throughput sequencing of the 16S rRNA gene to assess the relationship between these communities and the biogas composition. This microbial identification revealed a typical AD composition consisting of the following six phyla: Actinobacteria, Bacteroidetes, Chloroflexi, Euryarchaeota, Firmicutes, and Proteobacteria. Furthermore, through the identification of Methanobacterium and Methanosaeta , two methanogenesis pathways (hydrogenotrophic and acetoclastic) were pinpointed. From a macroscale perspective, a multi-stage Gompertz kinetic model was used to describe cumulative biogas production. This model considered the complex nature of the OFMSW substrate in order to estimate the potential level of biogas production in the MAG using a weighted average that was based on the size of the population in each socioeconomic stratum evaluated (732.8 mL⋅g −1 VS). This novel contribution to the literature provides an estimation of the potential economic, energetic, and environmental benefits of treating the OFMSW produced in the MAG through AD. Through this approach, an estimated 8.5 MWh·year −1 of electrical power could be produced, translating into 1.13 million USD of yearly revenue and resulting in reduced GHG emissions (10,519 tonne CO 2eq ⋅year −1 ).

Vaccines have been produced in record time for SARS-CoV-2, offering the possibility of halting the global pandemic. However, inequalities in vaccine accessibility in different regions of the world create a need to increase international cooperation. Recent studies have shown a temporal increase in the neutralizing antibody potency and breadth to SARS-CoV-2 variants in coronavirus disease 2019 (COVID-19) convalescent individuals. Here, we examined longitudinal antibody responses and viral neutralizing capacity to the B.1 lineage virus (Wuhan related), to variants of concern (VOC; Alpha, Beta, Gamma, and Delta), and to a local variant of interest (VOI; Lambda) in volunteers receiving the Sputnik V vaccine in Argentina. Longitudinal serum samples ( N  = 536) collected from 118 volunteers obtained between January and October 2021 were used. The analysis indicates that while anti-spike IgG levels significantly wane over time, the neutralizing capacity for the Wuhan-related lineages of SARS-CoV-2 and VOC is maintained within 6 months of vaccination. In addition, an improved antibody cross-neutralizing ability for circulating variants of concern (Beta and Gamma) was observed over time postvaccination. The viral variants that displayed higher escape to neutralizing antibodies with respect to the original virus (Beta and Gamma variants) were the ones showing the largest increase in susceptibility to neutralization over time after vaccination. Our observations indicate that serum neutralizing antibodies are maintained for at least 6 months and show a reduction of VOC escape to neutralizing antibodies over time after vaccination. IMPORTANCE Vaccines have been produced in record time for SARS-CoV-2, offering the possibility of halting the global pandemic. However, inequalities in vaccine accessibility in different regions of the world create a need to increase international cooperation. Sputnik V is a recombinant adenovirus-based vaccine that has been widely used in Argentina and other developing countries, but limited information is available about its elicited immune responses. Here, we examined longitudinal antibody levels and viral neutralizing capacity elicited by Sputnik V vaccination. Using a cohort of 118 volunteers, we found that while anti-spike antibodies wane over time, the neutralizing capacity to viral variants of concern and local variants of interest is maintained within 4 months of vaccination. In addition, we observed an increased cross-neutralization activity over time for the Beta and Gamma variants. This study provides valuable information about the immune response generated by a vaccine platform used in many parts of the world.