How To Keep Food Fresh for Longer

By George Erdosh, Christian Science Monitor. Posted November 8, 2007.

My mother went to the farmers' market every Saturday morning and sometimes also midweek, if she could slip out of the busy shoe store she owned and managed. As a kid I enjoyed the market so much that I frequently volunteered to be her basket carrier and manager of her change. The market was four blocks from our house, and we couldn't buy anymore than we could comfortably carry.

You couldn't -- and still can't -- beat that for freshness. But today, you can't beat a supermarket for convenience. There are things you should know, and things you can do, however, to keep the food you buy at a supermarket as fresh as possible.

Food-market distributors know how to keep foods fresh -- if not by natural means, then with the help of an arsenal of chemicals. Supermarket managers know how to keep meat, produce, and fruit looking their best -- and anything with the slightest hint of degradation is mercilessly trashed.

Not that I am critical of supermarket foods: I insist on buying the freshest foods possible and still buy at the supermarket even though their foods cannot hope to approach farmers'-market quality. But how many of us can find a farmers' market, a good butcher, an artisan baker, a reliable seafood store, or a quaint little cheese shop nearby?

Supermarket foods are acceptable: unblemished, shiny, perfect fruits and vegetables are kept at ideal temperatures in misty conditions so they will stay fresh-looking for days. Then there's cherry-red meats, plump golden-yellow poultry, and bright-looking seafood sitting comfortably atop beds of ice. The dairy case groans with a mind-boggling selection of hermetically sealed containers (single servings to family size), all utterly fresh.

"Fresh," of course, is subjective.

Since 1993, "fresh" has had a federal and legal definition from the Food and Drug Admin°©istration. "Fresh" means the food has not been processed in any way, nor frozen, heated, or preserved. It means that the food is basically in its raw form. (A few exceptions exist: It's OK to spray a moisture-sealing wax coating on some fruits.) According to federal guidelines, the terms "fresh frozen" and "frozen fresh" are allowed if the food was totally fresh when it was frozen quickly.

With good storage, fresh foods can remain fresh two times, even three times longer than improperly stored food. Red meat, such as beef, lamb, and pork, has long, tightly knit muscle fibers and is slower to deteriorate under microbial attack, but because of its specific fat composition, it is susceptible to the effects of oxygen. Poultry has shorter, looser fibers that microbes penetrate more easily -- poultry spoils faster than red meat. Fish and seafood are very short-fibered and loosely woven, and microbes attack them quickly and efficiently. They are among the most perishable of all foods we eat. Keep all meats, poultry, and fish cold, but when carrying and storing fish in particular, think "ice cream." Neither fish nor ice cream should ever warm up.

Meat, poultry, fish love the cold

Store meat and poultry in the coldest part of the refrigerator, near the bottom. Keep fish on a bed of ice, as they do in market fish displays. That way, the fish or seafood stay just above freezing. If you keep draining off the melted water and replacing the ice, fish stay fresh for several days.

Don't underestimate freezing as a freshness preserver for meat. Under perfect conditions, red meat may stay fresh for millennia. A mammoth frozen in Siberian ice was as fresh as the beef in your butcher's display case when it was discovered 20,000 years later.

Vegetables and fruits generally like it cold, but not all of them. Tropical fruits, for example, shiver and suffer in refrigeration temperatures. They are best stored cool but outside the refrigerator.

"Humidity plays an important role in keeping foods fresh," says Jerry Rose, general manager of refrigeration at General Electric. "Most fruits, vegetables, meats, and cheeses prefer an environment high in humidity."

Don't suffocate fruits and veggies

Fruits and vegetables respire; they breathe in and out. In a closed plastic bag, they soon suffocate. When storing them, leave the plastic bag open or punch holes in it.

Salad greens are loose-fibered and quick to spoil. Wash them thoroughly, then wrap them tightly in a cotton towel. Place the towel-wrapped greens in a plastic bag and refrigerate. They'll have enough air, and plenty of humidity, now. Greens stored this way stay fresh for close to a week.

Don't keep potatoes in the fridge, though, as the low temperature will cause them to turn sweet (their starch converts to sugar). Instead, store them in a dry, cool place.

The same goes for whole onions and garlic. But once they've been cut, refrigerate them in an airtight container.

Mushrooms prefer paper to plastic

Mushrooms are special: They detest too much moisture. In a plastic bag, they drown in their own liquid in a couple of days. But they keep well close to a week if refrigerated in a closed paper bag.

Everyone knows that dairy products need refrigeration, but hard, low-moisture aged cheeses, like grating cheeses (Parmesan, Romano), are the least susceptible to spoilage because they don't contain enough moisture for bacteria and mold to thrive. The higher its moisture, the faster a dairy product spoils. Cottage cheese, cream cheese, and mozzarella are among the highest-moisture cheeses.

Eggs have their shells as a sturdy protection against all attacks. They don't spoil easily, but they keep longer and stay fresher in the refrigerator. (A few decades ago, cases of eggs would sit unrefrigerated on market floors.)

A tip for refreshing stale bread

Baked goods vary. Yeast breads, bagels, and their cousins go stale faster in the refrigerator (never store yeast products in the fridge) and slowest in the freezer. They stay reasonably fresh at room temperatures, says Harold McGee in his outstanding reference volume, "On Food and Cooking: The Science and Lore of the Kitchen." That's why our great-grandmothers had bread boxes on their counter tops. Here's a tip: Should your loaf of yeast bread get stale, refresh it in a medium oven (350 degrees F.) for 10 minutes; five minutes for rolls. Sprinkle it with a little water before you put it in the oven to replenish lost moisture. They emerge warm and crusty -- almost like new. (No, it won't work in a microwave.)

Most nonyeasty baked goods store well on the counter if tightly wrapped to prevent drying out, unless they have an icing that requires refrigeration. Many baked goods freeze well and taste perfectly fresh after defrosting.

White flour has a shelf life measured in years, if not decades, but whole wheat flour that contains the oil-rich wheat germ becomes rancid if not refrigerated, particularly in warm weather. This is true of brown rice for the same reason. Sugar and salt keep forever. Dry legumes, such as beans and lentils also have a very long life when stored in a dry place.

Buy herbs and spices unground

Smart cooks buy herbs and spices in unground form and crush or grind them as needed. In this form they stay fresh for years, but not much longer than six months if ground. Store all spices and herbs in tightly closed containers away from heat (storing them above your stove is the worst place).

When you buy fresh herbs, keep them like cut flowers. Trim off the bottoms of the stems to expose fresh surface and place them in a small container with water, cover loosely with a plastic bag, and store in the refrigerator. Change the water and recut the stems as needed.

See more stories tagged with: health, food, freshness, produce

George Erdosh is a correspondent of The Christian Science Monitor.

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