Campylobacter, for example, is a bacterium that does not harm chickens but causes illness in human beings and even death in the vulnerable. A nanoparticle to go into chicken feed is being developed at Clemson University, South Carolina, which would latch on to Campylobacter, ensuring that it is excreted by chickens, so making the bird safer to eat.

Another potential use of nanotechnology directly in food is to use it to improve emulsification, meaning that products such as mayonnaise don’t separate out even if they have a low-fat content.

Nanoscale silica spheres filled with molecules of a fluorescent dye have been developed to go into meat packaging, where they will detect the presence of the deadly E. coli 0157 bacteria. When contact is made, the spheres literally light up, resulting in a change in packaging colour.

Nanomaterials added to PVC films can also prevent spoilage by UV light.