FOX 12 Investigators went grocery shopping and discovered a disturbing trend.

Out of 15 grocery stores surveyed, FOX 12 found that all but one of them was selling food past the expiration date on the package.

FOX 12 purchased more than $500 worth of expired bacon, applesauce, chicken patties, cheese, protein bars and baby food.

The owner of Tenly Market in southeast Portland told FOX 12 Investigators that she puts a black "X" on the items past date so people won't buy them or she throws the items out.

However, when FOX 12 crews checked the store, with the owner's permission, they found several overdue food items, meat six months past the expiration date and ice cream that was best before February 2006.

But it is not illegal to sell food past the package's stamped expiration date.

According to the grocery industry, shoppers are not at risk from old food.

"We're allowed to sell things past the pull date," said Joe Gilliam of the Northwest Grocery Association in Wilsonville.

Gilliam said the pull date on food packaging is not an expiration date. The date instead refers to quality, not safety.

"The manufacturer may not want the product on the shelf past the pull date, but it's not going to make anyone sick," said Gilliam.

The law also said stores can sell perishable foods, like yogurt, milk, meat and cheese, past the pull date, but they have to put it aside and mark it, announcing it's past due.

None of the stores FOX 12 surveyed marked any of the food items purchased.

The president of the Grocery Association said the stores probably left them out by mistake, not meaning to trick shoppers.

"They don't want to sell you anything that's not fresh," said the president. "They want you to be happy when you leave the store."

Still, shoppers FOX 12 talked to said they are surprised that stores are not keeping closer watch on expiration dates.

"That's crazy," said one shopper.

"I think they should do it where they can't sell expired food at all," said a second shopper.

According to experts, shoppers should use the date on the packaging as a guideline and keep perishable food cold after purchasing. Click here for more information on outdated food safety.

Below is a list of the stores FOX 12 Investigators surveyed. Click on a store for a list of the items purchased and the response from store representatives.

• Albertson's
• Bales' Thriftway
• Food 4 Less
• Fred Meyers
• Grocery Outlet
• Haggen
• Knott Market
• New Seasons Market
• Pearl Market
• Safeway
• Tenly Market
• Whole Foods
• WinCo
• Zupan's

During a shopping trip to the Trader Joe's at 39th Avenue and Holgate on June 5, 2007, there were no food items found past their pull date on the shelves.

Click here for outdated food guidelines and tips.

Click here for additional food safety links.