Identifying nanoparticles in food
Nanotechnologies are increasingly used in the food chain. Engineered nanoparticles (ENPs) may enter food from use of additives in food packaging as well as from environmental contamination. Reliable analytical methods are needed to assess possible risks as well as to enforce current legislation, e.g. on food labelling. At the start of the EU-funded project 'Nanoparticles in food: Analytical methods for detection and characterisation' (NANOLYSE), methods for the detection and characterisation of ENPs in food were limited. Now, at the end of the project, significant strides have been made in this important field. The aim of the project was to develop methods for reliable detection and analysis of ENPs in food. It also set out to develop and validate reference materials against which to compare various types of ENPs. Researchers selected representative ENPs from each type of material, for example, nano-silver and nano-silica, to demonstrate their new methods. Methods that could be implemented in existing food analysis laboratories were prioritised. A two-tiered process of identification and analysis was developed and validated using these representative particles. The first tier focuses on rapid screening, while the second provides reliable identification and quantification of specific ENPs. Researchers built software to provide semi-automated analysis of electron microscope images, which could reliably detect ENPs in various foodstuffs. Identification and quantification of inorganic ENP was achieved by multidetector field flow fractionation and single particle ICP-MS. Another aspect of the project was to develop reliable ways to handle organic nanoparticles (protein-, lipid- or carbohydrate-based), which are more fragile than their inorganic counterparts. All methods were thoroughly validated. Finally, NANOLYSE developed reference materials to use in conjunction with the analytic methods developed during the project lifetime. In the long-term, NANOLYSE contributes to food safety and transparency by enabling to screen foods for the presence of potentially harmful ENPs.
Keywords
Nanoparticles, food, detection, characterisation, food analysis
