Perhaps you consider yourself a socially and environmentally responsible individual: you separate all your recyclables, turn off the water when you brush your teeth, and buy shampoo packaged in postconsumed plastic. Now you are about to sit down to a well-earned "fresh" fruit salad of papayas, strawberries, and grapes. But, the papayas are from Mexico, the strawberries are imported from Ecuador, and the grapes are from Chile. How environmentally responsible is it if your food has traveled a greater distance than you have on any particular day? And how has this travel affected the nutritional content?
It's been estimated that food eaten in this country travels an average of 1,500 miles from the farm to the dinner table. This is an economic and environmental concern; at this rate, fuel and local agricultural resources could run out for future generations.
One step you can take is to get a year-round guide to local fresh produce, which can be obtained from your state's Department of Agriculture. However, in much of the winter and early spring, the only local fresh produce available in northern latitudes falls in the apple, pear, root vegetable, cabbage, onion, or squash families. If you want other types of fresh produce at this time of year, one option is to can or freeze your own when they are in-season. In order to do this, however, you need canning and freezing equipment and a comprehensive knowledge of sanitation and storage techniques.
There is another, simpler alternative. The simple act of navigating your grocery cart through the canned and frozen produce section of your market can help save the earth and improve your nutrition! Frozen fruit and vegetables are shipped directly from the fields and orchards in which they are grown to a processor near the field. After they have been frozen or canned, they are preserved at the processor until a large bulk shipment can be made. Perishable fresh produce, on the other hand, needs to get to its destination quickly and must be shipped in smaller shipments and great distances, especially off-season. As mentioned, this is a very uneconomical process.
Fresh produce is shipped quickly enough to prevent spoilage. But, its nutrient content may be compromised. The longer fruits and vegetables are in transition, the more nutrients are oxidized into the air. The average time from field to your fruit or salad bowl is about 10-14 days. In contrast, produce that is frozen or canned sits only a couple of hours before its freshness and nutrients are locked in by freezing or canning.
The differences in the nutrition content of fresh versus frozen and canned foods are significant. Dr. Barbara Klein, a professor of foods and nutrition at the University of Illinois, found that frozen green beans retain a high percentage of their
content. On the other hand, "fresh" green beans that sit on a truck, wait on a loading dock at the supermarket, and then languish in your refrigerator, do not retain as much of their vitamin C content.
Klein found a similar scenario with a can of pumpkin. One cup of canned pumpkin has a huge amount of vitamin A—about 300 percent of the recommended daily intake (RDI). On the other hand, a cup of fresh, cooked pumpkin contains a much smaller amount of this vitamin. Part of the reason for the difference is that canned pumpkin contains less water than fresh; the canned version is a more concentrated source. Still, the potency of the nutrients in this and other canned vegetables are substantially higher than "fresh" ones that travel hundreds of miles, losing nutrients along the way.
Ever notice your frozen strawberries or canned pumpkin may be months old but they retain their bold colors when you do decide to use them? The reason, Dr. Klein explains, is that food processors often choose the brightest, most vivid colored produce right from the field. These fruits and vegetables are not only more pleasing to consumers, but also contain the greatest concentration of nutrients. These deeper hues signify a richer nutrient content.
The nutritional value of some foods is improved with canning.
Lycopene, an antioxidant found in tomatoes, is actually enhanced by the canning process. Lycopene is found naturally in tomatoes, but is better absorbed by the body from canned tomato products such as tomato paste, sauce, and chopped tomatoes.
One of the major drawbacks to using frozen or canned vegetables is that extra sodium and fat can sneak in. Those who need to watch their salt intake should look for low-sodium varieties of canned vegetables. Most vegetable-sauce combinations are high in fat, but you can create your own low-fat sauces with honey, flavored vinegars, herbs and spices, or low-fat cheeses. Although most frozen vegetables are packaged "au natural," you should check the label to be sure.
Summer is an excellent time to frequent local farmers' markets for fresh, nontransported produce. And in the winter you can treat yourself to a sliced papaya for a little extra sunshine. Just think about canned, frozen, or locally produced options before you do, and do not eat from the equator every weekday this winter. It is not just about saving natural resources—it is about your health and nutrition, as well as your wallet.