Woolworths has been fined in a South Australian court after admitting it sold food beyond the used-by-date.

The supermarket sold two packets of Asian-style lamb and rice at a store at Murray Bridge last May, date-stamped for expiry 13 days earlier.

Adelaide Magistrates Court was told the retailer had retrained staff as a result of the case.

The magistrate said the adverse publicity was more of a penalty than any fine.

But Woolworths was given a penalty of $7,500, which must to be paid to Murray Bridge Council, and no conviction was recorded.