There are calls for better labelling on meat products after a major supermarket company admitted to a packaging practice known as "gas flushing".
The practice involves pumping carbon dioxide and oxygen into the packaging of some meats to increase their shelf-life.
Progressive Enterprises, which owns Countdown, Foodtown and Woolworths, said it has been gas flushing for 15 years and packages around 10% of its meat products this way.
Brett Ashley of Progress told ONE News that gas flushing is usually applied to beef and lamb products.
He argued that it provided a better taste for the consumer.
"They do require ageing. Time actually makes the product that much better."
But others in the industry disagree.
Foodstuffs, which owns New World and Pak N' Save, said it doesn't gas flush fresh meat.
Grant Thornbury from the small Westmere Butchers shop also prefers to keep things fresh.
"Straight off the carcass, we cut it fresh here...and then we sell it direct. Doesn't get any fresher."
Thornbury questioned the need for gas flushing.
"I think in a way, it's kind of deceiving to make it look like it's fresh if it's not."
Currently it is difficult for customers to know if meat has been gas flushed.
One tell-tale sign is a plastic cover which is sealed all the way around the top. Meat which is untreated is wrapped with plastic that gathers at the bottom.
Progressive said it would consider labelling gas-flushed meat, if it was something that customers wanted.
Labelled or not, NZ Food Safety Authority said that the practice is safe as the gases used are present in the air.