Last updated at 08:08 13 December 2005

Apples are being sold in supermarkets up to a year after harvesting.

The "freshly-picked" fruit - stocked by chains including Sainsbury's - is treated with a chemical gas that stops it ripening during storage.

The process allows produce to be sold two to three seasons after being harvested.

Are you worried that your fruit is so old? Tell us below on reader comments

Agrofresh, the US firm behind the SmartFresh chemical as it is known, says it locks the taste in the apples, preserving the quality.

However critics insist stores should stock fresh local fruit.

Vicki Hirst, of Friends of the Earth, said: "Good food needs no artificial chemicals. There should be investment in local and regional seasonal products."

Tim Lang, professor of food policy at London's City University, described SmartFresh as a "brilliant but surreal use of science".

He said: "They are using technology to play around with the seasons. The food may look fresh but it isn't."

The treatment, which is used in more than 25 countries, stops apples producing ethylene, the natural ripening agent that softens fruit before it rots. The nutritional content of fruit is also preserved during storage.

EU approval

It was approved by the EU this year despite evidence it is carcinogenic in very high doses.

Producers using it include Domex, which ships American apples to Britain.

Domex marketing director Eric Patrick said: "It has given us the confidence to say that Red Delicious apples taste as good in July or August as they did when they were harvested in October."

Year-old apples are common in US supermarkets but it is thought that most apples on sale in Britain are no more than six months old.

Imported apples can, however, spend nine months in storage before arriving in this country.

They may then lie in a warehouse for two to three months.

This means that some apples in British supermarkets can be as much as a year old.

A Sainsbury's spokesman said: "Traditionally, apples have been laid down in chilled environments to preserve their quality and taste. SmartFresh, which enhances that process, is used by apple growers who supply the whole of the retail industry."

The chemical is also used on bananas, melons, tomatoes and avocados, but only extends their shelf-life by days or weeks.