Low energy X-rays inspect food

A new inspection system developed by European researchers can help to ensure that the only thing in people’s dinners is the food itself.

The so-called Modulinspex system is based on a novel detection technology which enables the use of low-energy, rather than high-energy, X-rays to provide very detailed images at a high contrast at inspection speeds up to 500mm/sec.

The system can be used to check seals on food wrappers, locate packaging defects and find foreign particles of any size in any kind of food, from maggots in apples to grains of sand in bread.

Until now, X-ray inspection technology used by food processors was dominated by high-energy intensity systems not unlike those used to scan luggage at airports. Higher-resolution alternatives, using low-energy X-rays, had not been used because it took too long to scan the produce and would slow the rapid pace of production in modern processing and packaging plants.

But by developing a new CdTe CMOS detector that can detect the X-rays in a low-energy system, the researchers have been able to build a system that is capable of taking 300 images per second, enough to capture a crisp image of products moving on a conveyor belt at half-a-metre per second.

Once captured, the images are then scanned via inspection software that can automatically detect any irregularities accurately and quickly. Since the X-ray images have a resolution of 0.1mm – 16 times better than existing high-power systems – it is possible to detect objects as small and fine as a herring bone.

Even in an era of high food standards and sterilised packaged produce, foreign bodies and packaging flaws are more common than most people realise, said Jørgen Rheinlænder, the co-ordinator of the Modulinspex project and managing director of Denmark-based InnospeXion.

‘Most X-ray luggage scanners at airports are virtually identical because one type works anywhere,’ Rheinlænder explained. ‘In the food industry, however, everyone has different requirements depending on the speed of the production line, the type and size of products being scanned and hygiene regulations.’

Hence the new system has been developed in a modular fashion, allowing hardware and software components to be adapted to suit the needs of any producer in the food industry.

The consortium of companies involved in the project has already sold three of their systems to companies in Spain, the UK and Denmark. The systems were bought after the project partners held a demonstration at the Scandinavian Food-PharmaTech exhibition last November in Denmark.

Curiously, none of the three systems that were sold are being used in the food sector, confirming, in Rheinlænder’s view, the broader range of applications for the technology. In the UK, for example, the system is being used by a company to inspect filters, while in Denmark it is being used to check the quality of fur used to make coats.

‘The market for this technology is truly enormous,’ Rheinlænder claimed. ‘In the food industry alone we can expect growth rates in excess of 20 per cent, and we also see a market for using it in manufacturing, to inspect seals on car components, for example, or to check for counterfeit products.”

The Modulinspex developers received funding from the EU’s Sixth Framework Programme for research.

Source: ICT Results