LSU AgCenter Nutritionist Explains Various Date Labels On Foods

Elizabeth S. Reames  |  7/29/2005 3:08:12 AM

News You Can Use For August 2005

Most people are familiar with the "sell-by" date on foods. Other date labels may not be so obvious, says LSU AgCenter nutritionist Dr. Beth Reames.

Product dating is not required by federal regulations, but if a calendar date is used, it must express both the month and day of the month (and the year, in the case of shelf-stable and frozen products). If a calendar date is shown, there must be a phrase explaining the meaning of that date such as "sell by" or "use before."

"Open dating" on a food product is a date stamped on a product’s package to help the store determine how long to display the product for sale. It also can help the consumer to know the time limit to purchase or use the product at its best quality.

Reames says open dating is found primarily on perishable food such as meat, poultry, eggs and dairy products. "Closed" or "coded" dating might appear on shelf-stable products such as cans and boxes of food. A sell-by date tells the store how long to hold the food for sale. You should buy the food before the sell-by date expires.

A "best-if-used-by (or -before)" date indicates best flavor or quality. It is not a safety date and does not indicate when a food should be purchased.

A use-by date is the last date recommended for peak quality. The date is determined by the manufacturer of the product.

Closed or coded dates are packaging numbers that enable manufacturers to rotate their stock as well as to locate their products in the event of a recall. They aren't meant for the consumer to interpret as use-by dates.

"Except for use-by dates, product dates don’t always refer to home storage or use after purchase," Reames says, explaining, "Even if the date expires during home storage, perishable foods should be safe, wholesome and of good quality, if handled properly and kept in the refrigerator or freezer."

Foods can develop an off odor, flavor or appearance from spoilage bacteria. If a food has developed such characteristics, you should not use it. Also, if foods are mishandled, foodborne bacteria can grow and cause foodborne illness - before or after the date on the package. For example, if hot dogs are taken to a picnic and left out for several hours, they would not be safe to use, even if the date hasn’t expired.

Federal regulations require a use-by date on the product label of infant formula and the varieties of baby food under FDA inspection. If consumed by that date, the formula or food must contain not less than the quantity of each nutrient as described on the label.

Formula must maintain an acceptable quality to pass through an ordinary bottle nipple. If stored too long, formula can separate and clog the nipple.

Dating of baby food is for quality as well as for nutrient retention. Just as you might not want to eat stale potato chips, you wouldn't want to feed your baby meat or other foods that have an off flavor or texture. Do not buy or use baby formula or baby food after its use-by date.

Reames says to follow these tips to be sure the food you eat is top quality:

• Purchase the food before the expiration date. For perishable food, take it home immediately after purchase and refrigerate or freeze it promptly. Refrigerators should be kept at 40 F or below, and freezers should be set at 0 F or below.

• Follow handling recommendations on the product. If a product has a use-by date, follow that date. If product has a sell-by date or no date, the product may be stored in the refrigerator and then cooked or frozen within recommended time of purchase. Recommended refrigerator storage times of ground beef, ground poultry and poultry is one to two days. For beef, veal, pork and lamb, it’s three to five days.

Once a perishable food is frozen, it doesn’t matter if the date expires, because foods kept frozen continuously are safe indefinitely.

If an egg carton has an expiration date printed on it, such at "EXP May 1," be sure that the date has not passed when the eggs are purchased. This is the last day the store may sell the eggs as fresh. On eggs, which have a federal grademark, such as Grade AA, the date cannot be more than 30 days from the date the eggs were packed into the carton.

As long as you purchase a carton of eggs before the date expires, you should be able to use all the eggs safely three to five weeks after the date YOU PURCHASE them.

Cans also may display open or calendar dates. Usually these are best-if-used-by dates for peak quality.

In general, high-acid canned foods such as tomatoes, grapefruit and pineapple can be stored on the shelf 12-18 months. Low-acid canned foods such as meat, poultry, fish and most vegetables will keep two to five years, if the cans remain in good condition and have been stored in a cool, clean, dry place.

For additional information about food safety, contact the Extension agent in your parish. For information on related family and consumer topics, click on the Family and Home link on the LSU AgCenter homepage, at


On the Internet: LSU AgCenter:

Source: Beth Reames (225) 578-3929, or breames@agcenter.lsu

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