Chemical technology news from across RSC Publishing.
04 January 2008
An ink that changes its colour when exposed to oxygen could help shoppers decide if their packaged food is fresh.
Oxygen is the enemy of fresh food because it causes food to degrade and bacteria need it to grow. Hence, much of today's packaged food comes in a protective atmosphere of gases such as nitrogen - with oxygen almost totally removed.
Andrew Mills and David Hazafy at University of Strathclyde, UK, have developed an irreversible solvent-based blue ink, which upon activation with UV light, loses all its colour and becomes oxygen sensitive; it will only gain its original colour upon exposure to oxygen.
- Andrew Mills, University of Strathclyde, UK
'An oxygen-sensitive ink, such as ours, could be used to show if the modified atmosphere remains intact, first at the packaging factory, then at the supermarket, ensuring faulty, damaged or tampered packages are not sold,' said Mills. The customer themselves will be able to pick up the food and tell instantly if it has be spoiled.
Link to journal article
Also of interest
Food of the future could come wrapped in smart plastic that detects contamination - and then biodegrades once thrown away.
A material that changes colour when exposed to oxygen could be used to indicate whether packaged food is still fresh, its inventors claim.