A dash of lemon keeps the salmonella away

An extra dash of lemon juice to home-made mayonnaise could help prevent salmonella poisoning, according to a team of food researchers, at Leeds Metropolitan University.

They studied the effect on salmonella when using citric acid such as lemon juice in making mayonnaise and looked at the ratio of egg yolk to citric acid and whether this had any impact on the safety of the finished product.

"Our main finding was that the amount of salmonella increases as the ratio of egg yolk to citric acid decreases. The less egg you use, the lower survival time for salmonella," said Alan Edmonson of the food research group. "People should use 20ml of lemon juice per egg yolk to avoid poisoning."

In 1997, Salmonella caused 44 deaths and about 50,000 cases of food poisoning in the UK.