Shoppers be warned as 'fresh produce' sitting on Australian supermarkets shelves could have been there for almost a year, with the consumer advocacy group Choice calling on consumers to be vigilant on their shopping trips.

Choice said on Tuesday that in some cases, apples being sold on the supermarket could have been harvested many months ago while meats are still being sold following considerable periods of the cattle's or lamb's slaughter.

While many Australians prefer fresh offerings from the shelves, Choice said that shoppers must be extra careful when picking on their favoured products but with the group's recent findings, it might be wise to buy frozen foods instead of the more appealing fresh produce.

Choice spokesman Ingrid Just reminded food shoppers that the availability of fresh produce throughout the year is not impossible anymore as advancements in food technology enabled producers to deliver even the seasonal fruits and vegetables at any given time.

Mr Just explained that most fruits and vegetables available in Australia were sourced from abroad, meaning they were harvested, stored and shipped in the country long before they reach the ideal stage for eating.

With the help of new technology, Choice said that a months-old apple could still look, feel and even taste fresh as if it was picked from a tree on the same day, thanks mostly to the chemical 1-methylcyclopropene (1-MCP).

Producers reportedly employ the substance on their fresh produce to delay the ripening of fruits and vegetables, extend their shelf life but at a cost of lesser flavour and less nutrients.

Choice gave advisory to consumers that in such situation, the better options are frozen or canned goods, which offer more premium in quality and nutrition.

Also, the consumer group is advising Australians that meat could be vacuum-packed and stored with the help of nitrogen and carbon dioxide to arrest the onset of micro-organisms and render lamb cutlets to last by up to 112 days and chilled beef by up to 44 days.

As an alternative, shoppers could consider visiting butchers and vegetable shops where they could get high-quality produce or better yet, buy produce that are in line with the prevailing season.