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Imaging techniques to identify food adulteration: proof of concept using pasta

Scientists from the Government Chemist programme describe the application of non-destructive approaches to food authenticity testing

Scientists from the Government Chemist programme have recently published a peer-reviewed paper in the journal of Food and Nutrition Sciences describing the application of imaging techniques as non-destructive approaches to food authenticity testing.

Food adulteration presents a significant challenge to the food industry. Adulteration is typically performed for financial gain, for example by substituting cheaper ingredients for more expensive versions, or providing false or inaccurate descriptions on the label. To ensure the consumer receives what they are paying for and to satisfy regulators, foods must be tested to ensure their authenticity.

Pasta products are typically based on durum wheat, a more costly wheat species considered to be ideal for pasta. EC regulation allows up to 3 % contamination with alternative species, such as common wheat, without further labelling requirements. Authentication of pasta is currently performed using molecular biology-based techniques. These techniques focus on DNA as the target analyte and, although effective, are time consuming, destructive, and require significant specialist training.

Using the adulteration of pasta as a model example, the paper by Wilkes et al (Food and Nutrition Sciences (2016) 7:355-361, doi:10.4236/fns.2016.75037) shows the application of multispectral and hyperspectral imaging techniques to food authenticity testing. This feasibility study demonstrated that these imaging techniques were capable of rapidly distinguishing between durum wheat and the adulterant common wheat variety and assigning percentage adulteration levels.

The results outlined in this paper demonstrate the potential for spectral imaging-based adulteration testing of seeds and grains to augment existing standard molecular approaches for food authenticity testing, providing a fast, non-destructive and high throughput approach.

Funding

Funding for this work was provided through the UK Department for Environment, Food & Rural affairs (Defra project FA0136 “Feasibility study for using rapid and automated spectral imaging for food authenticity testing”) and the UK Department for Business, Innovation & Skills as part of the Government Chemist Programme 2014-2017.