Ready to eat?

Most packaged salads are labelled as pre-washed, even "triple washed", and ready-to-eat straight from the bag. Should you really just serve and eat?

To reduce the risk of contamination, manufacturers usually wash salad leaves in a chlorine rinse - a process some UK green groups say is good reason to avoid bagged salad. Modified atmosphere packaging (MAP) may also be used to slow the growth of bacteria and extend the shelf life of the product. This packaging technique involves removing oxygen and often replacing it with a mixture of ozone, carbon dioxide or nitrogen.

But these processes aren't fail-safe. Bagged salads overseas have been linked to illnesses caused by salmonella and e.coli. While the New Zealand Food Safety Authority says there are no reports of illness from MAP foods here, its advice is to treat bagged salad like any other fresh produce. This means washing before use.

Only one company (Fraisbon Foods) puts a label on the salads it packs, recommending consumers wash them before eating. Fraisbon packs three of the salad brands we bought: Krispkut, Freshzone and Econo Pack.

Too posh to wash?

Ready-to-eat salads are cashing in on our convenience culture and critics say they're another sign of the growing distance between people and their food. Have we really become too lazy to wash our own veges?

Even if you're happy to do the washing yourself, whole lettuces seem harder to find these days. The bagged stuff is storming supermarket shelves and is a multi-million dollar market. Horticulture New Zealand says lettuce sales now rank third out of all vege sales, bettered only by potatoes and tomatoes.