Australian food scientists are developing flexible packaging which protects the entire package, rather than just the lid or opening, and alerts consumers when it has been tampered with.

Consumers might not detect tampering in flexible packaging that has been punctured by something as small as a syringe needle. This new packaging actually changes colour and indicates to the consumer that it has been interfered with.

Dr Robert Steele from Food Science Australia explained: “We are working on an indicator film sandwiched between two polymer films. When the film is punctured the availability of oxygen to that centre layer allows a dye that is usually pink to become clear – an ‘anti-bruise’ if you like.

"Around the puncture area becomes clear due to the action of light and oxygen which photo-oxidises the dye to a colourless compound.” The film also has applications for more rigid packaging.

By correspondent Matthew Brace, in Sydney