Selecting and Pretreating Fruits
Select fresh and fully ripened fruits. Immature produce lacks flavor and color. Overmature produce can be tough and fibrous or soft and mushy. Drying does not improve food quality. See Table 1 for approximate yields of dried fruits.
Thoroughly wash and clean fruits to remove dirt. Sort and discard any fruit that shows decay, bruises, or mold. Such defects can affect all foods being dried.
Pretreating fruits prior to drying is highly recommended. Pretreating helps keep light-colored fruits from darkening during drying and storage and it speeds the drying of fruits with tough skins, such as grapes and cherries. Research studies have shown that pretreating with an acidic solution or sodium metabisulfite dip also enhances the destruction of potentially harmful bacteria during drying, including Escherichia coli O157:H7, Salmonella species and Listeria monocytogenes. Several methods can be used.