The frozen food manufacturer has spent £4 million overhauling its range in order to guarantee that all 130 of its products are completely free from artificial colourings, flavourings and preservatives. The company says that it has dropped about 100 artificial ingredients including modified starches and thickeners.
In addition, Birds Eye says that it is reducing salt levels in ready meals by 16 per cent and the saturated fat content of the oil used to prepare products such as fish fingers by five times. Birds Eye also points out that the process of deep freezing has the naturally preserving effect of maintaining the nutritional value of food.
For example, Birds Eye beefburgers no longer contain E621 and E223, which are otherwise known as the flavour enhancer monosodium glutamate and the preservative, sodium metabisulphate. The two chemical additives have been replaced by rosemary extract.
The company is preparing to spend £25 million to publicise the move, which it believes will help it to side-step growing concern about additives. The Birds Eye campaign, which carries the slogan: "We don't play with your food", establishes the company as one of the first major European food processor to guarantee that their products are chemical-free.
The move is the latest in a significant push towards healthier food. Heinz for example said last month that it would launch a 'Reduced Sugar & Salt' version of Heinz Baked Beans. The product will be 50 per cent lower in salt than standard Heinz Baked Beans.
Birds Eye however claims that the move is in direct response to specific consumer concerns about artificial additives. Recent studies have linked some additives to childhood tantrums, and E numbers are increasingly being linked to issues such as obesity and heart disease.
Vyvyan Howard, a senior lecturer in toxicology at the University of Liverpool, who is overseeing a study on the effects of E numbers, told the UK's Independent newspaper: "My own view is that I wouldn't touch them. On a precautionary basis we should remove them from our food.
"Almost all E-number additives have no nutritional value. They have been tested one at a time but they certainly haven't been tested in combination, as they appear in foodstuffs. We simply don't know what their long-term effects are."
However, attempts have been made to establish whether additives really do lead to behaviour disorders and other problems. Scientists from the University of Southampton for example recently recruited 277 three-year-old children, whose parents kept them on a diet carefully chosen to be free of the additives.
In certain weeks, the children were then given a daily drink that either contained the additives and a benzoate preservative or an identical looking and tasting fruit drink. Neither the parents nor the children knew which type of drink was being given although the study design meant that they knew when they were being tested.
Reporting their findings in the June 2004 issue of the Archives of Disease in Childhood journal, the scientists said that while most parents did indeed report more disruptive and inattentive behaviours on those weeks the children received the drinks with additives (even though the parents did not know which drink was being taken), some also reported poorer behaviour by their children even when they had only been given the pure fruit drink.
The findings suggest that benefits may arise from removing these additives from children's diet, but the researchers stressed that a number of questions remained to be answered, not least why parents reported a noticeable effect from the drinks but clinical tests failed to show any behavioural differences.
One possibility, put forward by the scientists, is that the tests were not sufficiently reliable with children of this young age, although it could also be the case that those families completing the study may not have been representative of all families or that the effects produced by the pure fruit drink (a placebo effect) were large.
Bird's Eye is one of the UK's leading ready meal manufacturers. In fact the company is the largest brand in the frozen food market, which - excluding ice cream - is worth more than £3.7bn. Four out of five family freezers have products from Birds Eye.
The firm is part of the Anglo-Dutch consumer goods conglomerate Unilever, which last year made profits of £2.8 billion. Last year, the UK spent £12 billion on pre-packaged and processed foods.