By Julie Garden-Robinson, Food and Nutrition Specialist

NDSU Extension Service

A couple of years ago, my family and I visited a living history museum in the Midwest. My kids weren’t particularly thrilled about the prospect of learning something while on vacation, but they adapted fairly well.

Actors in period costumes talked with us as though we were all living in the late 1700s. We interacted with fur traders who were trying to coax a fire to light so they could make a meal. We watched Native Americans building canoes, stitching clothing from animal skins, and drying meat, corn and berries.

I think my kids forgot about checking their cell phones for text messages as they were immersed in history. They were amused by chipmunks scampering nearby, and they played with some early “gaming equipment” (sticks tied with leather strings and made into rackets).

In early history, refrigerators and freezers were not readily available to help prevent food spoilage. Food dehydration became one of the earliest forms of food preservation. Dehydration allowed people to have portable, lightweight and safe food to enjoy during cold seasons.

Dehydration probably was discovered by accident when early civilizations left food out in the sun and wind. When food dries, the food will not spoil as quickly because bacteria and other organisms need some moisture to grow. Mold, however, grows on foods with little moisture.

Because of the renewed interest in gardening and local food production, food preservation has increased in popularity. Food varies in moisture content and density, so dehydration is less precise than other types of food preservation.

Drying fruits and vegetables and making fruit leathers are fun activities for kids and adults. If you have kids or grandkids, you may have noticed how quickly they gravitate toward the commercial fruit leathers. These snacks are easy to make at home with seasonal fresh fruit.

The following fruits were rated as “excellent” or “good” by the University of Georgia for preparing fruit leather: apples, apricots, berries, cherries, nectarines, peaches, pears, pineapple, plums and strawberries. Other fruits (blueberries, cranberries) in combination can provide a good end product, too.

Because of increasing concerns that bacteria may survive the drying process, fresh fruits must be treated properly so leathers are safe to eat. Not only does heating increase the safety, but color may be better retained as a result. Follow this procedure for preparing fruit leathers provided by the Colorado State University Extension Service:

• Select ripe or slightly overripe fruit. Thoroughly rinse soft-skinned fruits or scrub hard-skinned fruits under running water. Remove blemishes or defective parts, then peel apples, oranges, peaches, pears and similar fruits before pureeing. Remove seeds, pits and cores.
• Cut fruit into chunks and place in the top of a double boiler. Place water in the bottom of the double boiler and bring to a boil. Cover and steam for 15 or 20 minutes or until the fruit is soft and a thermometer placed in the fruit mixture registers 160 degrees F.
• Place cooked fruit in a blender. Add ½ teaspoons of ascorbic acid crystals or 2 tablespoons of lemon juice per 2 cups of fruit. If desired, add 1 to 2 tablespoons of honey, corn syrup or sugar per 2 cups of fruit. A small amount of spice (1/4 teaspoon cinnamon or a dash of nutmeg) also may be added per 2 cups of puree.

Note: Honey usually provides the best results when drying fruit leathers.

• Fruit leathers can be dried in a home food dehydrator following the manufacturer’s directions, or try an oven as long as the oven can maintain a temperature of 140 to 145 degrees.

Here’s an antioxidant-rich fruit leather to try. Be creative in your fruit combinations. For more information about food preservation, visit http://www.ag.ndsu.edu/food.

Blueberry-Applesauce Fruit Leather

1 c. blueberries

1 c. unsweetened applesauce

2 Tbsp. honey

Prepare blueberry puree by heating the berries to 160 degrees F in a double boiler. Place the heated berries in a blender and puree, then add the applesauce and honey. Spray a cookie sheet or similar flat tray with vegetable spray, or line the tray with plastic wrap or parchment paper and spray with vegetable spray. Another option is to use the specially designed plastic sheets for electric dehydrators, and follow the directions of the manufacturer. Be sure the tray has edges so the puree will not spill, and be sure that the dimensions of the trays are about 2 inches smaller than the dimension of the oven to allow for good air circulation. Spread puree evenly onto drying tray about 1/8 inch to 1/4 inch thick. A 12-inch by 17-inch cookie sheet holds about 2 cups of puree. Dry in an oven at 140 degrees or in a food dehydrator. The drying time for fruit leathers varies from 6 to 8 hours in a dehydrator and up to 18 hours in an oven. Leave the oven door open 2 to 6 inches, and place a fan near the open door to circulate air. Test for dryness by touching the leather in several places; no indentations should be evident. Lift the edge of the leather, which will adhere tightly to the surface, and peel it back about an inch. If it peels readily, it is dried properly. Roll it in plastic wrap and store in a cool, dry place for up to two months. If it molds, discard it.

Makes four servings. Each serving has 80 calories, 0 grams (g) of fat, 1 g of protein, 22 g of carbohydrate, 3 g of fiber and 0 milligrams of sodium.

(Julie Garden-Robinson, Ph.D., R.D., L.R.D., is a North Dakota State University Extension Service food and nutrition specialist and associate professor in the Department of Health, Nutrition and Exercise Sciences.)

NDSU Agriculture Communication – July 14, 2011