The Co-op chain has banned monosodium glutamate, and some E numbers from its own-brand food products.
Monosodium glutamate has been removed from the chain's crisps
The company said it had decided to remove the additives after concerns about their effects on children and others sensitive to their effects.
Food additives have been linked to hyperactivity in children.
But nutritionists said, while some might be intolerant to additives, there was insufficient evidence to link them to such behavioural disorders.
The Co-op ban covers 12 colourings, all of which are legally permitted.
These include Sunset Yellow (E110), Tartrazine (E102) and Quinoline Yellow (E104).
The Co-op has now banned a total of 21 colourings.
The chain said some are already illegal in the US and Japan.
Natural alternatives to the colourings and monosodium glutamate are now being used in many foods.
'Response to concerns'
But 27 products, including pink and white marshmallows, canned strawberries in syrup and Chinese style spare ribs, have been axed because no replacements could be found.
The store's crisps, and its chicken and mushroom pasta sauce are among the products no longer containing MSG - which is used as a flavour enhancer.
Sweets such as dolly mixtures and flying saucers no longer contain colourings such as Quinoline Yellow (E104), Cochineal (E120), and Indigo Carmine (E132).
Christine Clarke, head of Co-op brand, said: "The removal of MSG and these colours is in direct response to these concerns and the Co-op brand food range now has no added MSG and is free of these colours, even though we have had to de-list a number of products as a result."
A spokesman for the British Dietary Association said: "E numbers have all been given a European classification, which means they've all been tested and are safe.
"But the additives which the Co-op are removing are some of the prime suspects that do cause intolerances in a small number of people - although not as many as you might think.
He added: "It is pleasing that the Co-op has done this. But we would not want people to think all E numbers are bad."