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.