Acidic mayonnaise
Another trick, they said, is to mix the main ingredients in a slightly more acidic mayonnaise, which also stops the fillings from deteriorating. Highly perishable ingredients such as lettuce and tomatoes are not used.
“The product is as fresh on day 14 as it is on day one,” Ray Boggiano, the man behind the technique, was quoted as saying by the Daily Mail.
He said: “The science is not new. It’s all about using a protective atmosphere in the packaging. “It’s the same technology that is used in packaged sliced meats. That’s the basis.”
Booker, the leading food and drink wholesaler in the UK, is about to start supplying the special sandwiches to convenience stores and corner shops — bucking the trend by food producers to emphasise freshness.
“We’ve tested them thoroughly and they are nice to eat,” added Boggiano, a food technologist who has spent almost a year developing the special sandwich. However, nutritionist Dr Carina Norris said that the long shelf life may come at the cost of nutritional value.