Today the food we purchase is supplied, contained or wrapped in ever increasingly sophisticated food packaging materials. Long gone are the days when food and beverages always came in glass bottles, plain paper bags or cardboard boxes. Shoppers probably never stop to consider the benefits of modern packaging, the chemical substances used in the manufacture of the packaging, or the potential migration of chemical substances from the packaging materials into the food. Food packaging is classed as a food contact material (FCM). This more generic term includes any material that comes in to direct contact with food, so also includes containers for transporting food, machinery to process food, as well as kitchenware, such as Teflon™ coated frying pans and tableware.
Modern food packaging materials provide many benefits as described by Sara J. Risch in a publication titled "Food Packaging History and Innovations." Today, packaging materials are designed to fulfill multiple purposes including the protection of food products from external sources of contamination, the prevention of deterioration of the product by controlling the atmosphere around the food, and by inhibiting the growth of pathogens. Other benefits include the use of lighter materials, such as plastic instead of glass, to facilitate more cost-effective transportation.
Smart packaging can detect biochemical or microbial changes to the food to indicate spoilage, while nanotechnology is used to prevent spoilage in the first instance. For example, the use of antimicrobial nanoparticles of silver incorporated into the packaging material inhibits growth of micro-organisms, while nano titanium nitride added to bottles used for water and soda improves temperature and moisture stability. Even plastic films and bottles are available in many forms: PVC (poly vinyl chloride) is often used for bottled water, or LDPE (low density polyethylene) used for milk, while PP (polypropylene) bottles are used widely for a variety of products.
In an article by Sophia Griffiths, the latest trends in food packaging and plastic bottles are reported to include: renewable bio-based plastics and LiquiGlide™ coatings on the inside of bottles to allow viscous products, such as ketchup and other sauces, to move more easily across a permanently slippery surface to reduce food waste.
Not surprisingly there are several hundred authorised substances, including volatiles, semi-volatiles, non-volatiles, and elemental and complex mixtures, used in the manufacturing of food packaging materials. This creates the possibility of chemical contamination of the food via migration from the packaging. To ensure consumer safety, manufacturers of food packaging materials are required to conduct migration studies in compliance with regulatory guidelines as it is important to prevent the release of constituents at concentrations harmful to human health.
EU 10/2011 establishes a threshold of 10 ng/g of NIAS in food. In the U.S., the regulations for food packaging material are more complex because the types of raw and processed foods and conditions of use are separated.
Methods for the analysis of known substances of concern, such as Bisphenol-A (BPA) in plastic bottles and plasticizers (phthalate esters), are relatively well established. However, simply testing for known ingredients used to make FCMs is not sufficient; there is also a requirement to carry out a safety evaluation of the non-intentionally added substances (NIAS).
In Europe, Regulation (EU) No. 10/2011 on plastic materials and articles intended to come into contact with food includes the explicit requirement to assess the safety of all potential migrants, including the NIAS. These are the impurities, oligomers, degradation, and/or reaction products of the intended ingredients. Substances not specifically regulated by name must be subjected to risk assessment by the business operator according to internationally recognised scientific principles on risk assessment.
A white paper by Fera UK Ltd, titled “Safety Assessment of Food Contact Materials: The Role of High-resolution Mass Spectrometry in the Comprehensive Analysis of the Total Migrate” describes the issue of chemicals migrating into food from packaging materials, the need to assess the safety of those chemicals that migrate, and the role that high resolution mass spectrometry has to play in the related analysis.
In an article titled "Living in a Material World" in The Analytical Scientist. Prof Gilbert of FoodLife International Ltd, explained that producers now have a responsibility to show that they’ve done all they can to identify NIAS in FCMs. He stated that “the only technique you can really use is based on full scan data using high-resolution accurate mass (HRAM) mass spectrometry. LC Orbitrap and GC Orbitrap are the technologies we will see used more frequently in the non-target area and for packaging materials.” This short article is an interesting read covering the history, analytical drivers, regulations, and future direction of food contact materials.
Utilisation of Orbitrap Technologies for the Detection of NIAS
Electron impact and positive chemical ionisation with full-scan and MS/MS experiments, performed at high mass resolution (120,000 FWHM @ m/z 200), provided the selectivity for discrimination of analytes from co-eluting compounds and the mass accuracy needed for confident structural elucidation. These features, in combination with novel software algorithms for automated spectral deconvolution and compound ID, create a powerful solution for fast, confident and comprehensive chemical characterization of volatile and semi-volatile contaminants in food packaging materials.
The need for full-scan high resolution accurate mass acquisition for the highest confidence in the results from targeted and non-targeted workflows
The use of flexible fragmentation options for structural elucidation of NIAS
The use novel software tools, libraries and databases for high efficiency data-processing
So to answer the question, the evidence does suggest that Orbitrap-based technologies have the capability to provide comprehensive answers to the complex analytical challenge of the analysis of NIAS in FCMs.