Some foods such as apples, pears, peaches, and apricots dry better when pretreated. Pretreatment reduces oxidation,giving a better color, reducing vitamin loss, and lengthening shelf life. Research studies have shown that pretreating with an acidic solution enhances the destruction of potentially harmful bacteria during drying. Place cut fruits in a solution of 3¾ teaspoons of powdered ascorbic acid (or crush 20 500mg vitamin C tablets) or ½ teaspoon of powdered citric acid in 2 cups water for 10 minutes before placing on trays to dry. Equal parts of ottled lemon juice and water can be substituted for the above pretreatment.Other methods of pretreating fruit include syrup blanching,water blanching, and sulfiting. Syrup blanching involves simmering the prepared fruit for 10 minutes in a syrup of 1 cup sugar, 1 cup white corn syrup, and 2 cups water and letting it stand in the hot syrup for 30 minutes before draining, rinsing,and placing on drying trays. Syrup-blanched fruit is sweeter but
also stickier than fruit treated by other methods. Refer to a book on food drying for specific times and directions if you choose to blanch fruits. Although sulfites have been used in the past to prevent oxidation, this fact sheet does not include this method ecause sulfites are not recommended for use by individuals on restricted-sodium diets or who have asthmatic or respiratory conditions. Sulfited food should be dried outdoors for safety reasons.Some fruits such as blueberries and cranberries need to be dipped into boiling water to crack the skins. Be careful not to leave the fruit in the boiling water for too long or the fruit will turn to mush. Chill quickly after cracking skins and blot dry