I want to know the changes in nutritional value that occur when fresh fruits are dried. Thank you,
Eating fruits and vegetables fresh is the best way to get the most nutrients. Any processing can cause nutrient losses, which vary depending on the product and the processing conditions. Freezing, canning and drying can all result in losses of C, B vitamins and carotene (a precursor to vitamin A) since they are destroyed by exposure to heat and air.
With drying, for example, the common use of a sulfite treatment (the process in which the fruit is exposed to sulphur fumes from or dipped in a sulfate solution) prevents the loss of some vitamins, but causes the destruction of thiamin. Sulfites can also cause allergic reactions, so people sensitive to these preservatives should read ingredient labels carefully. Since January 1987 the FDA has required that sulfites be listed on the ingredient labels of the packaged foods that contain them. Blanching vegetables before drying (to destroy enzymes) results in some loss of Vitamin C, B-complex vitamins and some minerals because these are all water soluble. On the other hand, blanching reduces the loss of vitamins A, C and thiamin during dehydration and storage.
Dried fruits and vegetables have a higher concentration of sugar than their fresh counterparts because most of their water content has been removed. Therefore, there are more calories in dried foods on a weight-for-weight basis. 100 grams of fresh apricots have 50 calories, while 100 grams of dried apricots have 260. Carbohydrates, most minerals, fiber and proteins get concentrated, but are otherwise unaffected by drying.
Further nutrient loss can occur during storage unless the foods are properly packaged and stored. To keep the nutritional losses to a minimum, package your dried foods in airtight containers, store them at the lowest temperature possible, and consume them within several months to a year after purchase.
With all this information in mind, assuming your fruit was dried under the best of conditions, it has likely suffered some loss of vitamin C and carotene, but there are still plenty of nutrients left, and eating a dried fruit is still a good nutritional choice.
Sue Gilbert, M.S., Nutritionist