Wednesday, May 11, 2011

Food Expiration Dates: Should You Eat That?

Confused by food expiration dates? Figuring out when to toss that packaged poultry can confound even the smartest women, and the wide range of labeling standards don’t make it easier. Our Medical Detective is here to help. Whether it’s meat or dairy, fresh or canned, find out what a “use by” date really means – and how it can save you money…

That half-full container of milk in your refrigerator was date-stamped three days ago. A sniff test doesn’t turn your stomach and it hasn’t gone chunky. Should you take a chance and pour it over your kids’ cereal?

The experts say: Sure! In fact, many foods are just fine past their listed “sell by” dates.

“If it smells OK, the world won’t come to an end [if you eat it],” says Jeanne Goldberg, Ph.D., professor of nutrition at the Friedman School of Nutrition Science & Policy at Tufts University in Boston.

“It’s better to use food quickly before it expires – but a large part of your decision-making should be common sense,” she says.

In fact, expiration dates mean more to grocers than they do to consumers. Most packaged foods with dates stamped on them help store owners and manufacturers track the products. Dates and codes vary, and the government regulates almost none of it.

“Seventy percent of shelf-life dates on products are [manufacturer] guesses,” says Ted Labuza, Ph.D., professor of food science and nutrition at the University of Minnesota.

Yet most consumers would rather take a hit to their pocketbooks than eat food that’s “expired.”

“People don’t care what we say or if food smells fine,” says Kathy Bernard, a spokeswoman for the U.S. Department of Agriculture. “They can’t get past that date – if it’s expired, they throw it out.”

The labels aren’t easy to decipher either. Walking the aisles of a local supermarket recently, the Medical Detective found an “enjoy before” label on a carton of juice, a “sell by” label on refrigerated salad dressing, a “better if used by” label on a box of cereal, and a “use or freeze by” label on a package of ground turkey. (What does it all mean? See “Label Language” at the end of this article.)

Most of us sort through perishables at the market to get the latest possible use by date, Labuza says. But freshness often depends more on how quickly an item went from delivery truck to store-refrigerator case than the date on the package label.

“Ironically, the older product in a store may be the [fresher] one, depending how quickly it hit the refrigerator,” he adds. “[Reading labels] is no guarantee you’re getting a better product.”

Some foods last longer than their use by date, while others – such as meat – can go bad days before the label suggests it should.

Besides, the listed dates have more to do with a food’s quality than its safety.

“Safety is about avoiding the growth of pathogens [bacteria] that can cause infection or poisoning,” Labuza says. “Quality is about freshness, flavor and texture – whether your potato chips are crisp or soggy.”

How Long You Can Store Food
If you’re like most people, you care about flavor and safety. Wondering if that salmon is still OK, or if that Bush-era can of corn is edible? Here are expiration guidelines for 5 major food categories, along with a breakdown of what their labels really mean.

1. Steak, veal, pork and lamb (keeps for 3-5 days in the refrigerator after purchase).
Ground beef (keeps for 1-2 days in the refrigerator after purchase).

Nothing’s more worrisome than fresh meat – and for good reason. It spoils quickly and no one wants to spend the night hugging the toilet.

Meat is likely to have a “use or freeze by” or “best if used by” package label, which lists the last date recommended by packagers or grocers for eating at peak quality, according to the United States Department of Agriculture (USDA). Often, you can still use the meat after that date, though it may not taste as good.

But label dates won’t help you with a more important consideration: meat safety.

“Growth of bacteria is the main concern about the shelf life of meat and fish,” Labuza says.

When meat is improperly stored, “the number of bacteria doubles every 15-20 minutes,” he says. “You start with 10,000 bacteria per square centimeter on the surface and get to a million rather quickly. At that number, if you eat it, you throw up.”

The rate of decay depends on the amount of moisture meat is exposed to (less is better) and the temperature at which it’s stored. That’s why you shouldn’t leave raw meat out of the refrigerator or wait too long to consume it.

“The cooler you keep it, the longer it lasts,” Labuza says.

All meat should be stored below 40°, but Labuza keeps his in a separate garage refrigerator set at 32° so it easily outlasts the expiration date by several days, he says.

As a general rule, refrigerated meat should be cooked within a few days of purchase.

The exception is ground meat, which has a shorter shelf life and should be stored for only 1-2 days. It’s more easily contaminated by harmful bacteria such as E. coli and Listeria monocytogenes during processing – so even if it’s fresh, you need to cook it to an internal temperature of 160° to avoid illness, according to the USDA.

And remember, Goldberg warns: “If you keep raw meat in your car while riding around doing errands, it spoils even faster.”

You’ll know if meat has gone bad by an unmistakable vinegar or ammonia odor. It may also be slimy and the color may have started to fade.

Frozen foods remain safe indefinitely, but can lose quality over time, according to the USDA. Uncooked roasts, steaks and chops last 4-12 months, uncooked ground meat is good for 3-4 months, and bacon and sausage can be frozen for 1-2 months.

2. Raw poultry (keeps for 1-2 days in the refrigerator after purchase).

This bird should fly off store shelves promptly, experts say.

“Chicken spoils quickly,” Goldberg explains.

Bacteria such as salmonella, Staphylococcus aureus, Campylobacter jejuni and Listeria thrive on raw or undercooked chicken, multiplying quickly at temperatures higher than 40°. Only cooking (to 160° all the way through) can kill them.

Although not federally required, many stores voluntarily provide sell-by dates on poultry, after which they’ll remove it from shelves. But whatever that date says, you should use or freeze it within two days of purchase.

If you purchase a warm, roasted chicken from a market or food chain, make sure it’s hot when you buy it and use within two hours. Otherwise, cut it into pieces and refrigerate it in shallow, covered containers that don’t leave much space for air; then eat it within 3-4 days.

In the freezer, uncooked poultry lasts 9-12 months. But while freezing can stop further contamination, it won’t kill bacteria that’s already there.

That’s one reason to defrost frozen poultry in the refrigerator, Goldberg says: “Bacteria grow fast on the outside of the chicken or turkey, even when it’s frozen on the inside.”

3. Fish (refrigerate for 1-2 days after purchase; store frozen for 3-8 months).
Shellfish (refrigerate for 1-2 days; store frozen for 3-12 months).
Fish and shellfish leftovers (refrigerate for 3-4 days; store frozen for 3 months).

Raw fish, like meat and poultry, often has a use by date on the package label, and you shouldn’t ignore it because “fish has a short shelf life,” Labuza says.

But you shouldn’t depend only on that date either. Use your nose – smell that salmon before you grill or bake it.

You’ll know it has gone bad if it produces a strong fish odor and turns brown or gray around the edges. Fresh fish springs back when you press it; spoiled fish is mushy.

3. Dairy products (usage depends on the product and the geographical state in which it’s sold).

The federal government has no requirements for milk, yogurt, cheese and other dairy foods. About 20 states impose their own labeling rules.

Pasteurized milk, if stored in your refrigerator at the right temperature (below 40°) immediately after purchase, can last 3-7 days after the “sell-by” date. But there’s no guarantee – and it sometimes starts to smell before the expiration date, Goldberg says.

If it’s left out at a temperature above 40°, it can go sour fast. No matter when you bought it, if it smells bad, toss it, Goldberg says.

What about cheese? Hard varieties, such as Swiss, cheddar or blue, are good for up to six months after their sell-by dates. Cream cheese lasts about two weeks.

If there’s a little mold on the outside of a block of hard cheese, you don’t have to trash it. Save money by scraping it away (about 1/8th of an inch deep) and enjoying the rest.

4. Eggs (store in the refrigerator 3-5 weeks after purchase).

Fresh eggs have a long shelf life, as long as you refrigerate them quickly. Expiration or sell by dates are sometimes state-required, and USDA-graded eggs (AA, A or B) will display a pack date (the day the eggs were washed, graded and placed in the carton).

A while after the expiration date, the yolk may not stand at attention when you crack it open, but it’s still safe to eat, experts say.

“I’ve used eggs two months past the date on the carton,” Labuza says. “Just be sure to keep them cold.”

Egg shells are porous, so as moisture leaks out of them, the quality diminishes, Goldberg says. To help prevent this, she recommends storing them in the carton.

Throw away a cracked egg if you don’t know how it happened. If you’re the culprit, store the egg in a container, then use it in a baked recipe within a couple of days.

Hard-boiled eggs that are cooled before storing in the refrigerator last up to a week, according to the American Egg Board. But discard them if the shell color changes or feels slimy.

5. Canned, jarred and packaged foods (keep up to five years at room temperature).
Canned foods often are your safest food bet. They’ll last as long as five years past the “pack date” (usually printed as a code on the bottom), if your pantry is cool enough – ideally about 50°-70°, according to Texas A&M University. (Hint: Don’t put your pantry next to your oven, or even the refrigerator – it throws off a lot of heat.)

“I found a can of chicken in my pantry that was seven years old, and it was great,” Labuza says. “But another time I opened a can of condensed milk – not that old – and it was a solid brown gel. I dumped it.”

Foods with a high acid content, such as tomatoes and pineapple, don’t last as long. Use them within 12-18 months of the pack date.

If a can is sharply dented – or, especially, if it bulges outward – toss it immediately because there’s a good chance it has been infected with botulism, a potentially life-threatening bacteria.

Dry packaged foods also stay fresh a long time if they’re packed and stored well and aren’t exposed to moisture. For example, canned Pringles potato chips can last “2 or 2-1/2 years,” Labuza says.

Pasta and rice maintain their taste for about a year. Unopened bags of cookies are good for a few months.

Label Language
Confused by the language of food dates? This guide breaks down the codes:

“Sell by” date: Used by manufacturers to remind grocers when to remove products from shelves.

“Best if used by” or “Use by” date: Refers to the flavor or quality, not food safety. Past that date, the taste and nutrient content may have diminished, but it may still be edible.

(Note: The use by date on infant formula and some baby food is set by the federal government and refers to the period in which the product must contain the full amount of nutrients described on the label.)

“Expires by” or “Expiration date”: You should throw the product out past that date. No wiggle room.

“Pack date”: A code on cans and boxed foods indicating when the product was packed. It can be hard to decipher, but you can usually at least pick out a year.

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