Molecular dynamics study of the migration of Bisphenol A from polycarbonate into food simulants

Nanoscale Simulation of Plastic Contaminants Migration in Packaging Materials and Potential Leaching into Model Food Fluids

Polymers are the most commonly used packaging materials for nutrition and consumer products. The ever-growing concern over pollution and potential environmental contamination generated from single-use packaging materials has raised safety questions. Polymers used in these materials often contain impurities, including unreacted monomers and small oligomers. The characterization of transport properties, including diffusion and leaching of these molecules, is largely hampered by the long timescales involved in shelf life experiments. In this work, we employ atomistic molecular simulation techniques to explore the main mechanisms involved in the bulk and interfacial transport of monomer molecules from three polymers commonly employed as packaging materials: polyamide-6, polycarbonate, and poly(methyl methacrylate). Our simulations showed that both hopping and continuous diffusion play important roles in inbound monomer diffusion and that solvent-polymer compatibility significantly affects monomer leaching. These results provide rationalization for monomer leaching in model food formulations as well as bulky industry-relevant molecules. Through this molecular-scale characterization, we offer insights to aid in the design of polymer/consumer product interfaces with reduced risk of contamination and longer shelf life.

Evaluation and identification of chemical migrants leached from baby food pouch packaging

Multilayer plastic pouch (MLPP) has an estimated 9% annual increase of market growth. However, the migrants it can introduce to food has not yet been systematically studied. A total of 79 MLPPs for baby food were purchased from major retail outlets in Australia. The methodology for testing chemical migration followed the design of previous studies using four types of selected simulants according to the European Committee Regulation No. 10/2011 method. Four bisphenols and five phthalic acid diesters (PAEs) were detected, including the ones known for endocrine disrupting effect in human. Three intentionally added and 23 non-intentionally added substances (NIAS) were tentatively identified through a suspect screening procedure. Out of the 23 NIAS, neopentyl glycol - phthalic acid - 1,6-hexanediol - phthalic acid oligomer was identified for the first time with MLPP. A further two NIAS were detected for the first time in baby food related products. For 40% of the pouches where adipic acid - diethylene glycol was detected, the estimated exposure from consuming one pouch of food per day may exceed the threshold of toxicological concern established based on the Cramer classification.

A review on application of molecular simulation technology in food molecules interaction

Molecular simulation is a new technology to analyze the interaction between molecules. This review mainly summarizes the application of molecular simulation technology in the food industry. This technology has been employed to assess structural changes of biomolecules, the interaction between components, and the mechanism of physical and chemical property alterations. These conclusions provide a deeper understanding of the molecular interaction mechanism in foods, break through the limitations of scientific experiments and avoid blind and time-consuming scientific research. In this paper, the advantages and development trends of molecular simulation technology in the food research field are described. This methodology can be used to contribute to further studies of the mechanism of molecular interactions in food, confirm experimental results and provide new ideas for research in the field of food sciences.

Health risk assessment of endocrine disruptor bisphenol A leaching from plastic bottles of milk and soft drinks

Bisphenol A (BPA) is of major concern to public health due to its toxic potential and xenoestrogenic endocrine-disrupting effect. One of the major sources of BPA comes from the plastic bottles used to pack milk and soft drinks. The purpose of the present study was to assess and compare the risk associated with BPA transfer from plastic bottles to milk and soft drinks being stored in summer and winter conditions. A sensitive and reliable method of solid phase extraction cartridge packed with multi-walled carbon nanotubes (MWCNTs) was employed. In milk samples (supplied in plastic bottles) of winter season, BPA levels were 0.17-0.32 mg/ kg. In milk samples of summer season, BPA levels were 0.77-1.59 mg/ kg. In soft drink samples of winter, BPA levels were between 0.14 and 0.3 mg/kg. While in 4-month-aged summer soft drink samples, BPA levels were 0.7-1.02 mg/kg of food. The daily exposure dose (DED) of BPA in milk samples of winter season was 1.42-2.67 μg/kg which was below the standard tolerable daily intake (TDI) of 50 μg of BPA/kg of body weight as per USEPA. The DED of BPA in milk samples of summer season was 5.58-10 μg/kg of body weight which was also less than TDI. For soft drink samples, BPA from winter samples was ranged from 1.17 to 1.67 μg/kg of body weight while for summer 4-month-aged samples was 2.5-7.08 μg/kg of body weight. Both types of samples were still less than TDI of BPA.

Enhancing properties of PC/PA blends via compatibilization of olefin-maleic-anhydride copolymer based additives in masterbatch form

Polymer blending has been a simple and efficient way for designing and controlling the performance of polymeric materials using easily available types. Both polycarbonate and polyamide have excellent mechanical properties and thermal stability but their disadvantages such as limited chemical or water resistance can be eliminate by tailoring them. Main difficulties in processing of PC/PA blends are the poor compatibility and high moisture adsorption capacity of the two raw materials complicating processing and also deteriorating mechanical properties of the products. Compatibilizing additives such as olefin-maleic-anhydride copolymer based compounds used in the experimental work can help to overcome the abovementioned difficulties. To determine the processing conditions of the raw materials several drying temperatures have been tested and thermal degradation has been examined by FT-IR spectroscopy. Experimental compatibilizing additives based on an olefin-maleic-anhydride copolymer have been investigated to enhance mechanical properties of the blends prepared by extrusion moulding. Mechanical, rheological, SEM and FT-IR measurements have been performed and at least one additive has been found to be efficient in improving selected properties.

Identification of 24 Unknown Substances (NIAS/IAS) from Food Contact Polycarbonate by LC-Orbitrap Tribrid HRMS-DDMS3: Safety Assessment

Twenty-four substances, mainly NIAS, have been tentatively identified in food contact polycarbonate through the application a new, fast, and automated analytical strategy for the investigation of unknowns in food contact materials. Most of the identified compounds were plasticizers, slip agents, antioxidants, and ultraviolet stabilizers and fragrances, and the majority of them have not been previously identified in PC food contact materials. The workflow setup includes an intelligent data acquisition applied using LC-Orbitrap Tribrid-HRMS (MS3), with an automated data processing using Compound DiscovererTM. To obtain a high confidence identification of unknown substances, a very strict criterion has been established, which comprises exact mass, isotopic profile, MS2 match, retention time, and MS3 match. To check for the safety of the migration from the food contact polycarbonate, a risk assessment was achieved using the threshold of the toxicological concern (TTC) approach. Except for the slip agent hexadecanamide, the compounds tentatively identified do not represent a risk.

The occurrence of bisphenol compounds in animal feed plastic packaging and migration into feed

Animal-derived food plays an important role in human exposure to bisphenol compounds (BPs), potentially as a result of the presence of BPs in animal feed. Even so, there have been few studies regarding the source of BPs in animal feed. The objective of the present study was to assess both the occurrence of BPs in animal feed packaging and the migration of BPs from feed packaging into animal feed. Thirteen BPs were monitored in 30 used animal feed plastic packaging samples previously employed for different animal feedstuffs and made of polypropylene (PP) or polyethylene (PE). Six and two BPs were found in PP-based woven bags and PE-based films, respectively. Bisphenol A (BPA) was the predominant analogue with a wide range of concentrations in both the PP- and PE-based packaging. A migration experiment was performed and provided the first-ever confirmation that BPA is able to migrate from plastic packaging into solid feed. Both contact time and the initial BP concentration affected the extent of migration. These results expand our knowledge regarding the origin of BPs in the food chain and suggest that further study of the bioaccumulation of BPs in animals is warranted.