The measurements are based on the combined use of asymmetric flow field flow fractionation with inductively coupled plasma mass spectrometry and ultra violet multi-angle light scattering.
They enable the detection and characterization of inorganic nanomaterials with between 1-100 nanometers in size, added to complex samples, including food. The research forms the first systematic comparison and optimisation of extraction methods for silicon dioxide nanoparticles in food. In conjunction with this, LGC has developed procedures that mimic food preparation in real life to obtain meaningful results regarding size and size distribution of silicon
dioxide nanomaterials in the investigated food sample.
dioxide nanomaterials in the investigated food sample.
High impact of nanotechnology
"The impact of nanotechnology in the food industry is high," Heidi Goenaga-Infante, principal scientist at LGC, the UK’s designated National Measurement Institute for chemical and bioanalytical measurement, told FoodNavigator. "The incorporation of nanomaterials can be accidental or intentional. For example, nanomaterials have been added to food to decrease content of salt, sugar, fat without affecting food taste1. In particular, silicon dioxide has traditionally been used as an anti-caking agent in foods such as cake mixes, seasoning mixes, coffee creamers, and for clearing beers and wines."
Although nanomaterials have shown many beneficial properties to industry and consumers, there are concerns about the toxicological hazard which some might present. However, Goenaga-Infante claims there is no strong evidence for toxicity since there is a lack of standardised protocols to assess nanoparticle toxicity and exposure to humans.
To date, measurement research has focused on developing methods to characterise physical properties of nanomaterials in their powder forms or in simple matrices. Developing traceable methods and reference materials for quality assurance of nanoparticle characterisation in complex matrices would help support upcoming regulation and enable quality control of existing products, said Goenaga-Infante.
Guidelines on use of nanomaterials
The European Food Safety Authority and the US Food and Drug Administration are writing industry guidelines on the use of nanomaterials in food. They are also working on putting regulation in place within the next five years.
There are remaining challenges associated with the characterisation of nanomaterials in food, said Goenaga-Infante. "The need for differentiation between natural and engineered nanoparticles and the lack of reference materials and standards for method validation are still the most important."
Funded by the UK National Measurement Office within the Innovation, Research and Development Programme, LGC is working to overcome such challenges, she said "Important collaborators on this area of work are Exeter and Birmingham Universities. LGC has also been part of the steering group for the British Standard Institute on the preparation of guidelines for the Detection and Characterisation of Nanomaterials in complex samples."
Some of the results achieved by the team lead by Goenaga-Infante have been published in the Royal Society of Chemistry peer-reviewed Journal of Analytic Atomic Spectrometry (JAAS)2.
(1) Nanotechnologies and Food, House of Lords Science and Technology Committee, First Report of Session 2009-2010, vols. I and II.
(2) V. Nischwitz and H. Goenaga-Infante, J. Anal. At. Spectrom., 2012, on line article.
