- Meat and Poultry
- Fish and Shellfish
- Cream and Cream Products
- Eggs and Egg Whites
- Ice Cream
- Dairy Spreads
- Fruit, Fruit Products
- Sauces, Dressing, and Dips
- Condiments, Herbs & Spices, Spreads
- Ingredients for Cooking
- Prepared Foods
- Bakery Goods and Sweets
- Grains, Pasta, and Cereal
- FAQs on Bacteria
- What are bacteria?
- How can I avoid getting sick from a bacterial illness?
- How dangerous is a staph infection?
- Can I assume that if food smells bad its unsafe to eat and if it smells ok that it is safe to eat?
- How dangerous is botulism?
- How dangerous is listeria?
- How many types of bacteria are there?
- What foods are likely to be contaminated by listeria?
- What foods can give a person a staph infection?
- What foods can give a person botulism?
- Why do some bacteria make people sick?
- Why does refrigeration keep bacteria from multiplying?
- Can I avoid all contact with bacteria if I’m careful?
- How Many Bacteria Does It Take to Cause Illness?
- FAQs on Cookware
- Are Ceramic and Enamel Cookware Safe and Practical?
- Are Nonstick Coatings on Cookware a Health Risk?
- Do Cast Iron, Glass, Copper, and Titanium Cookware Have Any Disadvantages?
- Does Using Aluminum Cookware Increase the Chances of Developing Alzheimer’s Disease?
- Is Stainless Steel Cookware a Good Choice?
- Is the New Silicone Rubberized Cookware Safe?
- Nonstick Cookware: Is it Dangerous?
- What Brands of Cookware are Recommended by Experts?
- What Features Should I Look for When Selecting Cookware?
- What Should I Know about Selecting and Using Aluminum Cookware?
- FAQs about Definitions
- Exactly what is meant by the phrase perishable food?
- Defining Some Current Language about Food
- What Does the Word “Foodie” Mean? It Depends Who(m) You Ask
- What do “sell by,” “best by/before,” “use by” and “expiration” mean?
- What does the term shelf life mean?
- What's in Our Food? Maybe Processing Aids, Maybe not
- “Fresh,” “Natural,” “Processed”—What Do These Words Mean?
- FAQs on Dropped Food
- FAQs on Farmers' Markets
- Exactly what defines a farmers’ market?
- Farmers' Markets: Why They're So Popular; How to Find One Near Your Home
- How should I handle produce at home?
- What foods are sold with restrictions at a farmers’ market?
- What should I bring to the farmers’ market?
- What shouldn’t I do or eat at a farmers’ market?
- What signs indicate a sanitary farmers’ market?
- What time of day is it best to go to a farmers’ market?
- FAQs on Food-borne Illness and Mishandling of Food
- About how many cases of food-borne illness occur in the U.S. each year?
- Answer Key to “How Much Do You Know about Safe Handling of Food?”
- How Much Do You Know about Safe Handling of Food?
- I Left It Out Too Long! Can I Still Eat It?
- Should Your Grocery Card Track Food-Borne Illnesses?
- Sudden, Awful Intestinal Distress--Is it the Flu or a Foodborne Illness--or Both?
- What YOU Can Do to Avoid Food-borne Illness
- What does the phrase food-borne illness refer to?
- FAQs on Food Product Dating
- Are stores required, by law, to remove outdated items from their shelves?
- Do most consumers actually pay attention to the dating on foods?
- Does the “use by” date matter once the product is frozen?
- Is information on food longevity and safety available by phone?
- What are expiration dates?
- What do the terms closed dating and open dating mean?
- What if there is no date on a product, and I don’t remember if I bought it a month ago or ten years ago?
- What should consumers know about food product dating?
- When Did You Buy It? When Did You Open It?
- When to Throw Food Out? Not on the Use-By Date
- Who establishes these product dates?
- Who requires and regulates dating on foods?
- Why do “best by” and “use by” dates sometimes seem conservative?
- FAQs on Food Safety
- "Is It Safe To….?" FAQs Answered by our Advisory Board
- FAQs about Ground Beef, Seasonings, Olive Oil, Lemon Wedges, and Fish
- FAQs about Mushrooms: Are they Very Dirty or Very Clean?
- FAQs about Soft Cheeses--What's Safe, What Isn't
- FAQs on Food Safety and Nutrition
- FAQs on Raw Fruits and Veggies—the Answers Can Protect Your Wallet and Your Health
- Food/Meat Thermometers—What You Need to Know
- How Long Should Cheese Be Aged? Will the Rules Be Changed?
- How Long Will They REALLY Last? Part I: Non-perishables
- How Long Will They REALLY last? Part II: Perishables
- Imported Foods—What’s Safe, What’s Risky?
- Is It Safe? Is It Nutritious? More Survey Answers from Scientists
- Is It Time to Switch to Pasteurized Eggs?
- Is the Food Safety Modernization Act Making Our Food Supply Safer?
- More FAQs about Minimum Safe Cooking Temperatures: Pork and Other Perishables
- Sushi: Why Such a Short Shelf Life?
- Winter Food Storage—Can I leave It in the Car or in the Garage?
- Would You—Should You—Do You--Eat Irradiated Food?
- FAQs on Food Wrapping
- Are any plastic wraps or containers really “microwave safe”?
- Are some plastic wraps more effective than others?
- Can I refrigerate meat and poultry in its store wrapping?
- Can I use plastic freezer bags to store produce in the fridge?
- Can chemicals leach unto food from plastic wrap or containers?
- Do coated plastic bags really help produce last longer?
- Does aluminum foil give foods a metallic taste?
- Does exposure to aluminum cause Alzheimer’s disease?
- Everything You Need to Know about Wrapping Food Right
- How should fruits be wrapped before refrigeration?
- Is it safe to use aluminum foil in a microwave oven?
- Should I wrap raw vegetables loosely or tightly before refrigerating?
- What are some advantages and disadvantages of aluminum foil?
- What produce needs to be wrapped before refrigerating?
- What’s better for wrapping food—plastic or aluminum foil?
- Why does foil sometimes darken, discolor, and leave black specks on food?
- Will a foil cover help keep foods on the table hot or cold?
- FAQs on Freezing Food
- FAQs on Leftovers
- FAQs on Mold
- What is mold?
- Does mold ever grow on nonperishable food?
- Can I remove a moldy part from food and eat the rest?
- About how many different kinds of molds are there?
- How can I avoid getting mold on my refrigerated food?
- Is mold always visible?
- Are any molds harmless?
- What food groups are most susceptible to mold?
- What kinds of illnesses can result from eating moldy food?
- What kind of packaging protects foods from mold?
- What other safety tips will help prevent mold from growing?
- Why are some molds dangerous?
- FAQs on Organic Food
- What Is Organic Food?
- Are Organic Methods More Humane to Animals?
- Does Conventional Food Have a Longer Shelf Life Than Organic?
- Does Organic Food Taste Better than Conventional Food?
- Is Organic Food More Nutritious Than Conventional Food?
- Is Organically Grown Food Better for the Environment?
- What Do the Various Organic Labels Mean?
- What Important Contributions Has the Organic Movement Made?
- Which Are Safer: Organic or Conventional Food Products?
- Will Organic Baby Food Make Baby Healthier?
- FAQs on Oxidation: How It Affects Foods
- FAQs about Plastic Products Used with Food
- Pyrex® Glassware: Is it safe to use?
- Are plastic bags safe to use in the microwave?
- Are some plastic wraps safer and/or more effective than others?
- Are there any health risks from reusing plastic water bottles by refilling them with tap water?
- Are we eating chemicals from plastics along with our food?
- Can I microwave food in my plastic containers?
- Does the plastic used in water bottles pose a health risk?
- If I heat food in an open can, will that cause the plastic lining to leach chemicals into the food?
- Is it safe to heat frozen entrées in their plastic containers and with their plastic wrap?
- Is it safe to use plastic wrap as a covering when microwaving food?
- Is it safe to wash and dry plastic plates, cups, containers, and utensils in the dishwasher?
- Is there good evidence that BPA is harmful to human health?
- Of the plastic products used to store, heat, or eat with (wraps, bags, containers, silverware, plates, etc.), which contain BPA?
- What is BPA?
- Why is so much of today’s food packaged in plastic?
- FAQs on Preservatives
- What are Preservatives?
- All things considered, is our food supply safer or less safe because of preservatives?
- Are the preservatives in hot dogs and similar products health risks?
- What preservatives are known to cause allergic reactions?
- What are some common preservatives used in food?
- What food groups commonly have preservatives in them?
- Why are preservatives added to food?
- Will the label on the product tell me if it contains a preservative?
- FAQs on Washing Produce: Why and How
- Other FAQs
- Can chicken soup really cure a cold?
- Is Chocolate Good For You?
- Can Science and Technology Help You Save Food Dollars?
- FAQs Answered By Our Board Scientists: on Chickens, Bananas, Old Salad Dressing, and More
- FAQs about Food Price Increases
- FAQs about Products We Use with Food
- FAQs about Shelf Life: Tortillas, Pancakes, Wine, and More
- Food Fraud: Are you paying for scallops and getting shark meat?
- Is Cheese Addictive? Only If You Eat It
- Missing Chickens: Where Have All the Small Ones Gone?
- Nine FAQs about Food Labels
- Quiz Yourself! Check Your Knowledge about Food Temperatures
- Scientists Answer Two FAQs about Egg Safety
- Some Shelf Life Info, General and Specific (Spirits, Defrosted Veggies, Green Tea, and More)
- Syrup from a Tree or from a Lab--Which Should You Pour on Your Pancakes?
- Ten FAQs about the Prickly Pineapple
- What's New in Food? IFT Expo Offers Tasty Innovations
- What's on the Menu in Cuba?
- What’s in My Water? Answers to FAQs
- FAQs on Bacteria
- Books: Food for Thought
- Food Safety
- It Says "Use By Tomorrow," But You Don't Have To
- Ten Tips for Consumer Food Safety
- Food Allergies: Recognizing and Controlling Them
- “Is It Spoiled?” When in Doubt, Check It Out
- How To Keep Your Cooler Cool
- Recent Recalls: Salmonella Threatens 100s of Products
- STOP! Don’t Rinse That Raw Chicken!
- Sous Vide—A Better Way to Cook?
- Why You Need a Safe Cooking Temperature Chart and How to Get One Right Now
- “Myth-information” about Food Safety: You’d Better Not Believe It
- After The Storm: What You Can Save and What You Must Throw Out
- How to Protect Your Food During a Power Outage
- Meet Your Beef--Via Bar Code Info
- Organic Food, GMOs, the Safety of American Food, the Value of Use-By Dates, and More--Scientists Tell Us What They Think
- Raw chicken, Leftovers, Deli Meats, and More-- What Surveyed Scientists Said
- Tips About 4 Popular Beverages: Wine, Coffee, Water, and Soda
- Tips on Reheating for Safe, Yummy Leftovers
- Tips on Water Safety During and After a Storm
- Introducing our Advisory Board Scientists
- Produce: Handling Tips
- Seasonal Tips
- A Novel Method for Cooking a Turkey
- Crock Pot Cooking Tips for that Ideal Winter Dinner
- Cucumbers: for Cool--and "Cool"--Summer Treats
- Going Away for All or Part of the Winter? Prepare Your Kitchen for your Absence
- How To Grill Safely During the Summer
- How do summer squash and winter squash differ?
- New Year’s Resolutions For a Safer Kitchen
- Preserve the Taste of Summer by Canning—But Do It Safely
- Summer Food Fests Offer Much More than Calories
- Summer Party Tips: Baby Carrots (Using for Dips) Hot Dogs (Ditching the Guilt), and Watermelon (Finding a Ripe One)
- Tailgating: How to Do It Right
- Tips on Keeping Your Summer Fruits Flavorful and Healthy
- Shelf Life Tips
- Tips for Carry-along Lunches for Work and School
- Tips for Freezing Food and Freezer Care
- Cooking Frozen Foods
- Freezers And Food Safety
- Freezers And Freezer Burn
- Freezers And Nutrient Retention
- How Often Should You Defrost And Clean Your Freezer?
- How To Defrost And Clean Your Freezer
- How To Defrost Frozen Foods
- How To Freeze Foods: The Quicker The Better
- How To Wrap Foods For The Freezer
- Refreezing Frozen Foods
- What You Can Freeze And What You Can't--Or Shouldn't
- Tips About Genetically Engineered Foods
- Tips for Grocery Shopping
- Tips for Holidays
- Answers to Questions about Thanksgiving Dinner
- Chocolate Is Even More Healthful Than You Thought
- Enjoy St. Patrick’s Day Without Cabbage Stink
- Everything You Need to Know about Cranberry Sauce
- Food-Related Gifts Recommended by Experts (2014)
- Halloween Treats Even Parents Will Love
- Kitchen Gifts that Really Please
- Kitchen Gifts that Really Work
- Spring Celebrations: What’s on Your Menu?
- Suggestions for Handling Your Child’s “Trick or Treat” Treasures
- Tips for Winter Holiday Meals
- What NOT to Do With Thanksgiving Dinner
- Yikes! The Turkey Is Done, But the Guests Are Delayed! How Do I Keep My Thanksgiving Dinner Warm?
- Tips on Kitchen Equipment
- Tips for Refrigerating Food and Refrigerator Care
- Food Safety Facts
- How To Clean The Refrigerator
- How To Wrap Foods For Refrigeration
- How long can a pie be left unrefrigerated?
- Power Outage? Here’s What to Do with All That Food in the Fridge
- Proper Handling Of Produce In The Crisper(s)
- Proper Refrigeration Placement Of Raw Meat, Chicken, And Fish
- Six Tips for Extending the Shelf Life of Foods
- What Can and Can't Go In The Fridge Door
- Other Tips
- Microwave Cooking
- The 10 Most Dangerous Foods To Consume While Driving
- Are Your Kids Home Alone after School? Educate Them about Snacking
- Clever Inventions That Can Change Eating Habits
- Coffee, Juice, and Food in Central America
- Eggies™ to the Rescue?
- Ever Eaten “Glued” Food?
- Food Definitions: Umami, Locavore, Fruit, Heirloom, and Artisan
- Hot Dogs: What You Should Know about Them
- If You Don't Know Beans about Beans...
- In Defense of Processed Food
- Kids and Cooking: A Good Combo
- New Uses for Old Food: Try 'Em Out!
- Organic Farming and Organic Food: What Are the Benefits?
- Our Board Scientists Talk about 2015 Food Trends
- Portabella Mushrooms and Their Relatives: How to Handle Them
- Ten Exotic Fruits: Novel Treats to Drink and Eat
- Tips on Fishing and on Selecting Healthful Fish
- Tofu: Water Regularly, Consume Promptly
- What This Site Is All About and How to Navigate It
- What We're Eating This Year: Ancient Grains, Coconut Oil, Kale, and More
- About Us
- In the News
Food Preservation--Low-Tech Past, High-Tech Present and Future
Food preservation--in other words, extending shelf life--has been a widely-practiced human endeavor since the days of cave people. (Forget that sexist term "cave men.") According to the website PartSelect, cave folk who lived in cold locations froze fish, seal meat, and other small animals by storing them on ice. In warmer climates, drying was the ancient method of choice for food preservation. Later, to freezing, drying, and fermenting, the Romans added pickling and canning.
In modern times, science has provided additional ways to extend shelf life, especially techniques, currently widespread, that can keep foods fresh longer in the refrigerator. Now, scientists are working on ways to extend the shelf life of foods that are customarily refrigerated, making them safe and tasty at room temperature for longer periods of time. Read on to discover the "supersandwich" with a shelf life, at room temperature, of 3-5 years! But let's start with the somewhat high-tech processes that most consumers come in contact with regularly, though they may not realize it.
Reduced Oxygen Packaging (ROP)
"Air is the enemy of food," a scientist once told me. Like all generalizations, this one has some exceptions. However, in general, oxygen does increase chemical breakdown and cause microbial spoilage of many foods. What's one modern solution? Reduced oxygen packaging. Some examples in your grocery store today are cook-chill, vacuum packaging, and modified atmosphere packaging.
Cook-chill is a technique that fills a plastic bag with hot cooked food from which the air has been forced out. The product is then closed by using a plastic or metal crimp.
Vacuum packaging removes air from the package and then seals it so that a nearly perfect vacuum is created. The package is hermetically sealed, which prevents gases from entering or escaping. The most common hermetic packages are foods in metal or glass jars. However, our supermarkets now carry many foods that are already cooked, on plastic trays covered with plastic, and not frozen. Yet, they carry a "use-by" date of a week or two after the date they're put out for sale. These foods can be microwave heated in about 3-5 minutes, and, most people will agree, they taste better than frozen foods.
Modified atmosphere packaging (MAP) is another widely-used preservation method. It replaces some or all of the oxygen inside a food package with other gases, for example carbon dioxide or nitrogen. This technique can be used to extend the shelf life of many more products such as fish, pre-cut greens, cheese, bakery goods, dried fruit, and nuts. MAP has the additional benefit of reducing the amount of additives and preservatives needed to maintain safety and quality.
There is one problem with reduced-oxygen environments: they can be conducive to the multiplication of some bacteria that don't "like" oxygen, especially the bacteria that cause botulism. To avoid this risk, it's important to keep these foods properly refrigerated.
High Pressure Food Processing (HPP)
When they call this technique "high pressure," they aren't kidding. It utilizes up to 87,000 lbs. of pressure per square inch! That would crush a marshmallow or a strawberry, but many of the foods sold in today's American supermarkets have been subjected to this treatment, and the result is a tasty product that is safe and of high quality and that lasts (unopened) 2- 4 times longer than its untreated counterpart.
Millard (a company that processes many products using HPP) describes HPP as a "post-packaging, non-thermal, pasteurization method." Yep, you got it right. This procedure can actually pasteurize without heat. That's a big advantage because, when foods are heated to kill bacteria, the quality is diminished--for example, taste, texture, appearance, and nutritional value. Products treated with HPP retain their natural freshness. Another benefit of this method of decontamination is that it cuts down on the need for preservatives and additional chemicals to fight the bacteria that cause spoilage or illness.
What products have been treated with HPP? The process has been used on cooked ready-to-eat sliced deli meats, guacamole, tomato salsa, applesauce, orange juice, oysters. (Hormel uses HPP for meat, and Cargill uses it for ground beef.) The process is extremely beneficial for prepared foods, packaged deli meats, sausages, juices, dips, salsa, seafood, wet salads, salad dressings, fruits, and vegetables. Acidic foods are especially well-suited to HPP technology. On the other hand, foods that contain no moisture and those that have entrapped air are not candidates for this process.
MAP and vacuum-packed products are HPP-compatible and benefit from the process since HPP provides additional microbial kill and extended shelf life. The "use-by" date that consumers find on HPP products reflects the extended shelf life resulting from HPP processing.
HPP cannot yet give us shelf-stable versions (ones that don't require refrigeration) of low-acid foods such as vegetables, milk, or soup because the process does not destroy bacterial spores that could cause illness.
Here's a summary of the typical HPP procedure as explained by Ohio State University's Department of Food Science and Technology: The product is packaged in a flexible container (plastic pouch or bottle) and put into a high pressure chamber. The chamber is filled with hydraulic (pressure-transmitting) fluid, which could be water. The pressure from the fluid is transmitted through the packaging into the food, usually for 3-5 minutes. (The photo accompanying this article shows Millard HPP equipment.) After processing, the product is then refrigerated.
HPP has been used on food for a couple of decades now, and it keeps growing in popularity. In 2008, about 450 million pounds of food treated with HPP was commercially available worldwide.
Want to see HPP in action? Click here to watch a video of the operation at the Millard facility.
The Almost Indestructible Supersandwich
"Food that Lasts Forever" is the utopian title of a March 12, 2012 Time magazine article. Why would we want it to last forever? Considering the ever-expanding world population, many fear that the future food supply will be inadequate. More immediately, there are many situations today in which it would be a wonderful convenience to have more food that could last, if not forever, at least for several hours or days without refrigeration. More importantly, to provide for the needs of troops in the field, shelf life extension of unrefrigerated foods would be a great advantage.
Lauren Oleksyk, leader of the food-processing, engineering, and technology team at the U.S. Department of Defense Combat Feeding Directorate described for Time "the indestructible supersandwich." Its bread stuffed with pepperoni or chicken. Sounds pretty ordinary, doesn't it? But it's built to last for 3-5 years without refrigeration. To accomplish this feat, it's necessary to control all of these: moisture, atmosphere, and microorganisms. The researchers accomplished all three by using water-absorbing ingredients and edible polymer film to keep the bread dry and by tucking "packets of oxygen-scavenging chemicals in the outer wrapping." Furthermore, the packaging is made as impervious as possible, "with layers of heat-resistant polypropylene and metal foil." This may not sound delicious and nutritious to those who want their sandwiches "natural," but it's progress. Don't be surprised if, eventually, supersandwiches are available to purchase for your supper.
Time mentions many benefits that today's research on extending shelf life may bring, for example, cutting the need to grocery-shop to only once a month, rarely having to throw out spoiled food, and being able to buy fruits and vegetables at a lower cost. In the coming years, technology is likely to bring even more convenient, time-saving, (and, hopefully, money-saving) innovations to the goal of extending the shelf life of foods.
Catherine N. Cutter, Ph.D., Pennsylvania State University, Dept. of Food Science
Time “Food that Lasts Forever” March 12, 2012
fst.osu.edu "Preserving Food Through High-Pressure Processing"
PartSelect “Food Preservation Basics"
ohioline.osu.edu "High Pressure Food Processing Lab"
Department of Food Science and Technology, Ohio State University