.Drying Fruits and Vegetables Extension Educator, Family and Consumer Sciences Original
author: Dorris Herringshaw, Extension Educator, Family and Consumer Sciences, retire
Drying is the oldest method of preserving food. Throughout history, the sun, the wind and
a smoky fire were used to remove water from fruits, meats, grains and herbs.
Dried foods are tasty, nutritious, lightweight, easy to prepare and easy to store and use. The
energy input is less than what is needed to freeze or can, and the storage space is minimal
compared with that needed for canning jars and freezer containers.
Vitamin A is retained during drying; however, because vitamin A is light sensitive, food containing
it should be stored in dark places. Yellow and dark green vegetables such as peppers, carrots, winter
squash and sweet potatoes have high vitamin A content. Vitamin C is destroyed by exposure to heat,
although pretreating foods with lemon,
Dried fruits and vegetables are high in fiber and carbohydrates and low in fat, making them healthy
food choices. Dried fruit has a higher concentration of carbohydrate than fresh fruit; therefore, serving
sizes tend to be smaller. According to MyPlate and the USDA's Dietary Guidelines for Americans, ½ cup
of dried fruit is equivalent to 1 cup of fresh fruit.
To be certain of the final quality and consistent drying of foods, a dehydrator is recommended, especially
with unpredictable Ohio weather. Sharp knives and a food processor or blender will also make the drying
task easier.
guidelines call for blanching, steaming or pretreating foods. Equipment for these processes includes a deep
kettle with a lid and a wire basket, a colander, or an open mesh cloth bag to hold produce. A nonmetal bowl
is best for pretreating fruits and vegetables to prevent discoloring.
Select ripe fruit for drying. For best results, use fresh produce, free from blemish and mold.Even
slicing of food allows the dry air to circulate and dry the surface area of the food first. Cut foods into
⅛-inch to ½-inch slices. The higher the water content, the larger you should make the slice size.
Small slices of high-moisture foods such as watermelon would disappear when all the moisture
has evaporated.
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Pretreatments are recommended techniques used to make quality products. Pretreatments not
only prevent darkening and improve quality; they also cause the destruction of pathogens that
could cause foodborne illness —such as Escherichia coli O157:H7, Salmonella species and Listeria
monocytogenes. Pretreatments include dipping, blanching, cooking or candying.
Dipping prevents oxidation or color changes in fruits and vegetables. Dipping fruits in ascorbic
acid (vitamin C) is one of the safest ways to prevent fruit from turning brown, but its effects may
not last as long as sulfuring. Ascorbic acid can be purchased fromdrug or grocery stores, in powder.
Commercial fresh fruit stabilizers or mixtures can also be used, but they might not be as effective
and most are more costly. Dilute 1½ tablespoons of stabilizer in 1 quart water. Again, soak for 3–5
minutes, then drain and place on dryer trays. Refresh the solution after two times of soaking
produce.
Generally speaking, vegetables are great to dry because they contain less acid than fruits and can be
dried until they are brittle. When properly dried, vegetables contain only 10 percent moisture, and
no known microorganisms can grow at that level. Wash, peel and trim produce; then, cut into pieces
for drying (could be slices, sticks, cubes or shredded), taking care to remove any tough or "woody"
part of the item.
Blanching is recommended for vegetables, as it stops the enzyme action that controls the color and
flavor during storage. It also helps to decrease the drying time and cooking time at the other end
because the tissue walls of the produce have been relaxed and moisture can escape and re-enter
more easily.
Dried fruits are generally done when they reach about 20 percent moisture content. Because fruit
will be more pliable when warm, cool several pieces and test by folding the fruit upon itself; it
should not stick together. Berries should rattle when stored in a container. When drying is
complete, cool the fruit before storing, but don't leave out to gather additional moisture.
If food was dried outdoors, which is not recommended in the Ohio climate, there could be
eggs on the food from insects that touched the food during drying. To pasteurize and kill
the eggs post-drying, either place food in a freezer bag and freeze for 48 hours or heat the
dried food at 150°F for 30 minutes or 175°F for 15 minutes. Be careful not to scorch the
food.
Select vegetables at peak flavor and eating quality. This usually is just as they reach maturity.
Sweet corn and green peas, however, should be slightly immature so they retain their sweet
flavor before their sugars change to starch.
Water blanching is recommended over steam blanching or blanching in a microwave because
water blanching achieves a more even heat penetration than the other two methods. Plain water
or water with added citric acid may be used. Citric acid acts as an anti-darkening and anti-microbial
agent.
