By Jon Caswell
Fruits and vegetables are the very definition of "good for you." They’re high in vitamins, minerals and fiber and low in fat and calories. Eating a variety of fruits and vegetables can help you control your weight and your blood pressure. But for some of us, the process of selecting the best produce, storing it for freshness and longevity and preparing it in ways that get the most nutritional bang for our buck may seem challenging or complicated. Here are some tips to help you choose, store and prepare the good stuff.
When you eat a wide variety of colors, you get a wide variety of nutrients.
Organic vs. Conventional
In some circles, much is made of the distinction between organic produce (which is grown without using chemical pesticides and fertilizers) and the kind grown by conventional farming techniques that use those things.
There is some evidence that some organic produce is more nutritious. This may be because plants under stress from pests make compounds that are protective. That may add to the nutritional content, but the differences are not big.
"The bigger question is whether these small differences in nutritional value add up to better health, and the jury is still out on that," said Carl Winter, Ph.D. and UC Agriculture and Natural Resources Cooperative Extension food toxicology specialist at University of California, Davis.
While there are good environmental reasons for growing food without chemicals, one of them is not because of the pesticide residue left on the food. "The miniscule amounts of pesticide residue we find on conventionally grown produce indicates that it is safe," Winter said. "My biggest concern is that people may reduce their consumption of fruits and vegetables to avoid pesticides and that’s the worst thing they can do."
Think in color
Fruits and vegetables are full of "phytochemicals," which literally means chemicals from plants.
"The colors in our fruits and vegetables come from the phytochemicals in them," said Kristie Lancaster, Ph.D., R.D., associate professor of nutrition at New York University.
"Different pigments represent different kinds of nutrients."
When you eat a wide variety of colors, you get a wide variety of nutrients. Even the creamy white of a potato or a cauliflower or the inside of an apple is a color made by a phytochemical. Eating it gives you the benefit of that nutrient.
"Eating lots of colors is also great, because then you’re not eating the same thing all the time," Lancaster said.
Know how to pick ‘em
Kathy Means, vice president of the Produce Marketing Association, a trade group, recommends buying produce in season for the best price and flavor. See our Seasons of Eating infographic to learn about what’s in season when.
Means shared that different produce items have their own peculiarities. In general, choose produce that looks fresh. "Ask your produce clerk to help if you are unfamiliar with something," she said. "Thumping melons or tugging on pineapple leaves are not good ways to assess ripeness." Here are some more tips from Means:
- Choose a watermelon that is firm, heavy for its size and shows no signs of decay.
- Choose cantaloupe that has a sweet aroma and is firm to the touch.
- Look for honeydew that have a waxy feel and a smooth, spherical shape. They should be heavy for their size.
- Avoid those with noticeable soft spots. Only cantaloupe will have the sweet aroma.
- Choose firm citrus items that feel heavy for their size.
- Avoid shriveled items. But easy-peel citrus, like clementines, may have wrinkly skin, which is fine.
Fresh, canned or frozen?
It’s not always possible to buy and use fresh produce before it goes bad. Some canned or frozen fruits and vegetables can be just as healthy and satisfying. Frozen and canned vegetables are usually processed at the peak of harvest so their nutrition is similar to fresh produce. Rinse canned vegetables to remove salt and choose fruits in their own juices with no sugar added.
"When you remove the peel you will lose the nutrients found in the peel."
Most fruit will continue to ripen at room temperature. Putting it in the refrigerator stops that process. So if your bananas get to the stage of ripeness you like, and you can’t eat them all today, put them in the fridge. The skin will turn dark, but the banana will hold your preferred ripeness.
Ethylene gas is a natural gas that is part of the normal ripening process. Some fruits and vegetables naturally give it off, and you can use that to ripen other things. For example, if you want to ripen an avocado, put it in a paper bag, not plastic, with a ripe banana or apple. The ethylene from the apple or banana will help ripen the avocado more quickly.
Berries are very perishable and should be eaten promptly. The holes in their clamshell packaging promote proper air flow, so leave them there until you’re ready to use them.
For the most part, nutritional value does not increase as produce ripens.
Tips on freezing
Most fruits and vegetables freeze well, Means said. Prepare the item (e.g., chop the onion) so it’s ready to use when you take it out of the freezer. "Freeze things in specific quantities that you would use in recipes, like a quarter cup of chopped onion," she said.
You can put berries on a cookie sheet and freeze them, then put them in plastic freezer bags to keep them from sticking together.
Throw really ripe bananas (peeled) in the freezer to use in smoothies or baked goods.
Chop fresh herbs and freeze them by the teaspoon or tablespoon in water in ice cube trays. Pop out the frozen cubes and keep them in a freezer storage bag. Then when you need a teaspoon or tablespoon of rosemary or thyme, you can just toss the cube into the pot. "Basil will turn dark," she said. "And remember, produce that’s been frozen won’t have the same consistency as fresh. Frozen things are best used in prepared dishes, like using frozen berries in sauces or baked items."
Rinse, don’t soak
Of course, you should wash all the produce you bring home in order to eliminate microorganisms. "There are 48 million cases of food-borne illness in the United States every year," Winter said. "You don’t know who or what touched that piece of produce before you did."
Rinse all produce just before you use it, with the exception of leafy greens, which you can rinse when you bring them home and store in the fridge. Use tap water and don’t soak fruits and vegetables. Do not use soaps or bleaches. For more on safely handling produce, visit Partnership for Food Safety Education.
What’s in the skin?
To peel or not to peel — that is the question. "The skin or peel of many fruits and vegetables is high in minerals and phenolic compounds, which are antioxidants," said Diane Barrett, Ph.D. and UC Agriculture and Natural Resources Cooperative Extension food science specialist at University of California, Davis. "When you remove the peel you will lose the nutrients found in the peel."
In the case of potatoes, you’re mostly losing calcium and iron, while peeled apples shed their fiber and vitamin A.
Cooking method matters
The way you cook food also influences its nutritional value. A good rule of thumb is that the least heat for the least time preserves the most nutrients. Cooking things in water removes the water-soluble vitamins, "which are vitamin C and the B vitamins like thiamin, riboflavin, niacin and B6," Lancaster said. "Steaming vegetables is the best way to preserve their nutrients."
"Microwaving is one of the best ways to heat something rapidly because the waves pass through the entire product almost instantaneously, instead of slowly heating from the ‘outside in’ as with other methods of heating," Barrett said.
You can find the nutritional information on thousands of different foods prepared many different ways on the US Department of Agriculture National Nutrient Database website.
Because produce is very economical – especially if you buy what’s on sale and in season – you can use it to extend more-expensive foods like meat and cheese by making salads, soups and stews.
Remember the adage "An apple a day keeps the doctor away"? Well, it was wrong, way wrong. Here’s the correct produce prescription for heart health – Eat five fruits and five vegetables every day from as wide a variety as you can.
Struggling to get 4-5 servings each of fruit and vegetables every day? One serving of most items is a half cup, which isn’t much. (See our Fruits & Vegetables infographic for more on serving sizes.) Make half your dinner plate fruits and vegetables if you don’t want to measure out your meals.
You can eliminate calorie-dense snacks like ice cream, cookies and candy bars by substituting fruit. Put baby carrots and celery sticks in bags so they’re easy to grab.
Keep a variety of fruit out on the counter where you can see it. Let the fact that it will go bad stimulate you to eat it. If you store things in the refrigerator, put them up front. Don’t let them migrate to the back and become a science project. And remember, once in the refrigerator they won’t continue to ripen.
Eating your quota of fresh produce is not a sacrifice, it is the basis of good health, and that’s the best way to keep the doctor away.
This information is provided as a resource to our readers. The tips, products or resources listed have not been reviewed or endorsed by the American Heart Association.