Asda has defended its decision to remove aspartame from own-label products after Japanese food giant Ajinomoto launched legal action against the group for describing the controversial ingredient as "nasty".

In a move to attract health conscious consumers, Asda said it has taken "hidden nasties" out of its Good for You range.

"We have led the way in the last year by removing all of the artificial colours and preservatives from our entire range of own label food," a spokesperson for Asda told just-food today. "As part of that process we have also removed some of the ingredients that our customers tell us they don't want in their food. That includes aspartame."

Aspartame is used as a sweetener in a range of products, from soft drinks to yoghurt.

In a statement Ajinomoto said that it intends to take legal action to defend the ingredient's image against this "malicious falsehood".

According to the Japanese food group, legal papers have been lodged at the UK's High Court.

"Ajinomoto has tried to negotiate an agreement with Asda by which the retailer would stop its denigration of aspartame, but has not succeeded. Ajinomoto has taken this legal step to defend the reputation not only of the ingredient, but also of the many products that are sweetened with aspartame," Ajinomoto said in a statement.