Woolworths says it will change the way it labels fruit and vegetables after being named and shamed for describing imported produce as Australian grown.

The NSW Food Authority has slapped the supermarket giant and its rival Coles with fines for incorrectly labelling imported fruit as Australian produce in two Sydney stores.

A Woolworths store in Newington was fined $1540 after being caught selling lemons from the US as Australian grown, while a Coles outlet in St Marys received an $880 ticket for a similar infringement involving grapefruit from Israel.

Both have been placed on the NSW Food Authority's Name and Shame register for 12 months.

Woolworths, which says only 3 per cent of its fruit and vegetables comes from overseas, was quick to respond to the fine.