According to a report on BBC Online, tests by scientists at the national food research institute in Rome have shown that pre-packed salads do not boost levels of vitamin C in the body to the same extent as their fresh counterparts.

While the British Nutrition Foundation which publishes the BJN still recommends consumption of the salads for other nutritional reasons, scientists in Italy have found that MA techniques remove antioxidants in salad leaves which help protect against disease.

Blood samples taken from people who had consumed pre-packed salad leaves did not show any increase in vitamin C levels whereas those in people who had consumed fresh lettuce did.

The Italian scientists are therefore recommending further research into developing techniques able to control the bio-active content in salads.