Ascorbic acid (vitamin C) can be used to prevent fruit from oxidizing and spoiling. This will increase the shelf-life of dried fruits and help them to retain their color if it is done prior to dehydration. As a preservative, it does not work as well as sulfites, but is an excellent and healthy alternative for individuals with sulfite sensitivity.
Ascorbic acid can be purchased from drug stores powdered or in tablet form (check outlet stores or wholesalers for bargains on large volumes). This is also a common method employed in the food industry to keep freshly sliced fruit from browning when it must be prepared several hours before serving.
An alternative to using an ascorbic acid solution is to simply use fruit juices that are naturally high in ascorbic acid -- particularly lemon, orange, pineapple, cranberry, and grape juice. These juices will of course impart their flavors and colors to the fruit, so if this is undesirable, stick with mixing an ascorbic acid solution yourself.
If you use the powdered form of ascorbic acid, 1 teaspoon usually is equal to about 3000mg.
Directions for treating fruit with ascorbic acid:
- Crush 1500mg of ascorbic acid tablets for each 1 cup of solution you plan to use.
- Dissolve 1500mg (about 1/2 teaspoon of powdered ascorbic acid) into each 1 cup of water.
- Completely submerge the sliced fruit in the ascorbic acid solution for 3 to 5 minutes.
- Drain the acid solution and place the fruit on drying trays. Dry promptly.
- You can re-use the solution up to several times if you add additional acid (try adding 1/4 teaspoon, or 750mg ascorbic acid per 1 cup solution for each re-use)