February 1, 2007 Some low-moisture foods such as dried apples can be safe to eat even years after their expiration date, if properly stored, food chemists say. They verified this in a tasting experiment of 28-year-old rolled oats. Heat, moisture and light can degrade food's nutritional value.
The next time you find forgotten food in the pantry, don't just toss it. Keeping food past its expiration date may not seem like a good idea, but certain foods last a lot longer than you think -- years longer.
Food scientists now know that, when properly sealed, some dried food that's been sitting on shelves for years, could still be OK to eat.
"It lasts a lot longer than we thought," Oscar Pike a food scientist at Brigham Young University in Provo, Utah, tells DBIS.
That's good news for Leslie Probert, who joins the rising number of people stockpiling food for emergencies. "I'm just writing the date on these cans so that I can remember when they were purchased," she says. "This is a year's supply of food for a family of five."
Scientists have known certain foods like sugar and salt can be stored indefinitely, but wanted to learn the shelf life of other food like dried apples -- stored since 1973 -- tried by taste testers.
"I like to call it the emergency shelf life of the food, food that you'd still be willing to eat in an emergency," Pike says. "It's not as though it were freshly canned, but it's certainly edible."
He says the best foods to store are low in moisture, like wheat and powered milk. But keep all foods away from heat and light to stop it from going stale and losing nutritional value. "All the foods that we've tested have been stored at room temperature or below, so you want to avoid attic and garage storage."
In the study, researchers taste-tested rolled oats that had been stored in sealed containers for 28 years. Three-fourths of tasters considered the oats acceptable to eat in an emergency.
BACKGROUND: Food science researchers subjected a panel of human tasters to samples of very old food. They discovered that even 20-year-old dried milk and 28-year-old rolled oats were still edible -- and sometimes even tasted okay. So a lot of food well past the manufacturer's expiration date might still be edible for years or decades to come.
ABOUT THE STUDY: Food scientists have long maintained that certain foodstuffs -- salt, granulated crystal sugar, seeds, and wheat kernels, for example -- can be stored indefinitely at room temperature or below. But what about more processed grains, such as rolled oats? So the researchers prepared oatmeal from 16 samples of regular and quick-cooking rolled oats that had been stored up to 28 years in sealed containers.
A panel of tasters rated the oats on aroma, texture, flavor, aftertaste and overall acceptability. The scientists also analyzed the samples' nutritional quality. Tasters rated the quality of the old oats from 4.8 to 6.7 on an ascending scale from 1 to 9. Three-fourths of the testers considered the old oats acceptable in an emergency.
WHY DOES FOOD SPOIL? Processing and improper storage practices can expose food items to heat or oxygen, which is what causes deterioration. In ancient times, salt was used to cure meats and fish to preserve them longer, while sugar is added to fruits to prevent spoilage. Certain herbs, spices and vinegar can also be used as preservatives, along with anti-oxidants, most notably Vitamins C and E. In processed foods, certain FDA-approved chemical additives also help extend shelf life.
CONSUMER TIPS: If you're stocking up on food in case of an emergency, be sure to include lots of water: one gallon per person per day for drinking, cooking and personal hygiene. The best foods for stockpiling are canned or freeze-dried soups; dried meats, fruits and vegetables; ready-to-eat-cereals and crackers; peanut butter, granola, or trail mix; energy bars, cookies and crackers; powdered or evaporated milk; and basic stables such as sugar, salt, pepper, rice, coffee or tea. Use only food-grade containers, and make sure the storage area is cool and dry, since hot, humid environments speed up spoilage. Date and rotate foods at least once a year.
The American Society for Microbiology contributed to the information contained in the video portion of this report.
Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.