Safety by design of printed multilayer materials intended for food packaging

A review on takeaway packaging waste: Types, ecological impact, and disposal route

Rapid economic growth and urbanization have led to significant changes in the world's consumption patterns. Accelerated urbanization, the spread of the mobile Internet, and the increasing pace of work globally have all contributed to the demand for the food takeaway industry. The rapid development of the takeaway industry inevitably brings convenience to life, and with it comes great environmental pressure from waste packaging materials. While maintaining the convenience of people's lives, further reducing the environmental pollution caused by takeaway packaging materials and promoting the recycling and reuse of takeaway packaging waste need to attract the attention and concern of the whole society. This review systematically and comprehensively introduces common takeaway food types and commonly used packaging materials, analyzes the impacts of discarded takeaway packaging materials on human health and the ecological environment, summarizes the formulation and implementation of relevant policies and regulations, proposes treatment methods and resourceful reuse pathways for discarded takeaway packaging, and also provides an outlook on the development of green takeaway packaging. Currently, only 20% of waste packaging materials are recycled worldwide, and there is still a need to develop more green takeaway packaging materials and continuously improve relevant policies and regulations to promote the sustainable development of the takeaway industry. The review is conducive to further optimizing the takeaway packaging management system, alleviating the environmental pollution problem, and providing feasible solutions and technical guidance for further optimizing takeaway food packaging materials and comprehensive utilization of resources.

Understanding the complexity of deinking plastic waste: An assessment of the efficiency of different treatments to remove ink resins from printed plastic film

Plastic packaging is usually heavily printed with inks to provide functional benefits. However, the presence of inks strongly impedes the closed-loop recycling of plastic films. Various media have already been studied for the deinking of plastic films, but there is little scientific insight into the effectiveness of different deinking techniques. Therefore, this study aims to obtain a systematic understanding by measuring the liquefaction and maximum solubility of 14 chemically different polymer resins in seven different media typically used in plastic deinking, such as acetone, ethyl acetate, sodium hydroxide solution, cetyltrimethylammonium bromide solution, formic acid, sulfuric acid, and N,N-dimethylcyclohexylamine. Our findings show that acid-based media are able to remove a broader range of polymer resins. Organic solvents are particularly effective against acrylics and related polymer resins. The deinking efficiency tests on pure resins are also confirmed by deinking four printed plastic films containing different classes of polymer resins. A basic cost and environmental impact analysis is given to evaluate scale-up potential of the deinking medium.

Quality and Shelf-Life Stability of Pork Meat Fillets Packaged in Multilayer Polylactide Films

In the present study, the effectiveness of a multilayer film of polylactide (PLA), fully bio-based and compostable, was ascertained to develop a novel sustainable packaging solution for the preservation of fresh pork meat. To this end, the multilayer PLA films were first characterized in terms of their thermal characteristics, structure, mechanical performance, permeance to water and aroma vapors and oxygen, and optical properties and, for the first time, compared with two commercial high-barrier multilayer packaging films. Thereafter, the multilayers were thermosealed to package fillets of fresh pork meat and the physicochemical changes, lipid oxidation levels, and microbiological counts were monitored in the food samples during storage under refrigeration conditions. Results showed that the meat fillets packaged in PLA developed a redder color and showed certain indications of dehydration and oxidation, being more noticeably after 11 days of storage, due to the higher water vapor and oxygen permeance values of the biopolymer multilayer. However, the pH changes and bacterial growth in the cold-stored fresh pork meat samples were minimal and very similar in the three tested multilayer films, successfully accomplishing the requirements of the food quality and safety standards at the end of storage.

Characterization of Polyester Coatings Intended for Food Contact by Different Analytical Techniques and Migration Testing by LC-MSn

Polymeric coating formulations may contain different components such as cross-linking agents, resins, lubricants, and solvents, among others. If the reaction process or curing conditions are not applied in a proper way, these components may remain unreacted in the polymeric network and could be released and migrate into foods. In this study, several polyester coatings intended for food contact were investigated. Firstly, Fourier-transform infrared spectroscopy with an attenuated total reflectance (ATR-FTIR) spectrometer and confocal Raman microscopy were used to identify the type of coating. Then, different techniques, including gas chromatography coupled to mass spectrometry (GC-MS) and analysis by matrix-assisted laser desorption coupled to time-of-flight mass spectrometry (MALDI-TOF-MS), among others, were used to investigate the potential volatile and non-volatile migrants. Moreover, migration assays were carried out to evaluate the presence of monomers and to tentatively identify possible oligomers below 1000 Da. The analyses were performed by liquid chromatography coupled to ion trap mass spectrometry (LC-MSⁿ). Using the information collected from each analytical technique, it was possible to elucidate some of the starting substances used in the formulation of the polyester coatings analyzed in this study. In migration tests, several polyester oligomers were tentatively identified for which there is not toxicological data available and, therefore, no migration limits established to date.

Application of chromatographic analysis for detecting components from polymeric can coatings and further determination in beverage samples

Major type of internal can coating used for food and beverages is made from epoxy resins, which contain among their components bisphenol A (BPA) or bisphenol A diglycidyl ether (BADGE). These components can be released and contaminate the food or beverage. There is no specific European legislation for coatings, but there is legislation on specific substances setting migration limits. Many investigations have paid attention to BPA due to its classification as endocrine disruptor, however, few studies are available concerning to other bisphenol analogues that have been used in the manufacture of these resins. To evaluate the presence of this family of compounds, ten cans of beverages were taken as study samples. Firstly, the type of coating was verified using an attenuated total reflectance-FTIR spectrometer to check the type of coating presents in most of the samples examined. A screening method was also performed to investigate potential volatiles from polymeric can coatings of beverages using Purge and Trap (P&T) technique coupled to gas chromatography with mass spectrometry detection (GC-MS). Moreover, a selective analytical method based on high performance liquid chromatography with fluorescence detection (HPLC-FLD) for the simultaneous identification and quantification of thirteen compounds including bisphenol analogues (BPA, BPB, BPC, BPE, BPF, BPG) and BADGEs (BADGE, BADGE.H₂O, BADGE.2H₂O, BADGE.HCl, BADGE.2HCl, BADGE.H2O.HCl, cyclo-di-BADGE) in the polymeric can coatings and in the beverage samples was applied. In addition, a liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) method was optimized for confirmation purposes. The method showed an adequate linearity (R² >0.9994) and low detection levels down to 5 µg/L. Cyclo-di-BADGE was detected in all extracts of polymeric coatings. The concentrations ranged from 0.004 to 0.60 mg/dm². No detectable amounts of bisphenol related compounds were found in any of the beverage samples at levels that may pose a risk to human health, suggesting a low intake of bisphenols from beverages.

GC-MS Screening for the Identification of Potential Migrants Present in Polymeric Coatings of Food Cans

The coatings used in cans can release complex chemical mixtures into foodstuffs. Therefore, it is important to develop analytical methods for the identification of these potential migrant compounds in packaged food to guarantee the compliance with European food packaging legislation and ensure consumer safety. In the present work, the type of coating in a total of twelve cans collected in Santiago de Compostela (Spain) were evaluated using an ATR (attenuated total reflectance)-FTIR spectrometer. These samples were analysed after extraction with acetonitrile in order to identify potential migrants through a screening method by gas chromatography coupled to mass spectrometry (GC-MS). A total of forty-seven volatile and semi-volatile compounds were identified in these samples, including plasticizers, photoinitiators, antioxidants, lubricants, etc. Then, in a second step, a targeted analysis was carried out for the simultaneous determination of 13 compounds, including bisphenols (BPA, BPB, BPC, BPE, BPF, BPG) and BADGEs (BADGE, BADGE.H₂O, BADGE.2H₂O, BADGE.HCl, BADGE.2HCl, BADGE.H₂O.HCl, cyclo-di-BADGE) by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) with atmospheric pressure chemical ionisation (APCI) source. Among all the bisphenols analysed, only the bisphenol A was detected in four samples; while cyclo-di-BADGE was the predominant compound detected in all the samples analysed.