Preventing Discoloration when Canning Fruit
There is probably nothing more unappealing than a piece of perfectly ripe cut fruit that's oxidized or discolored, dark or brown. When fruit is cut, peeled, pitted or stemmed, the flesh is exposed to oxygen and a reaction occurs that causes the exposed areas to turn brown. Light-colored fruits, such as apples, apricots, nectarines, peaches and pears, are particularly susceptible to browning, but cherries may also darken when pitted, as will grapes after they are stemmed.
This reaction (oxidation) can be prevented by treating fruit with an antioxidant such as citric acid. You can use a commercial produce protector containing ascorbi acid (vitamin C) or mixture of ascorbic and citric acids.
You can protect your fruit from oxidation by slicing it directly into one of the following antixidant solutions, a liquid to keep your fruit from darkening.
- An ascorbic acid or citric solution: Make a solution with 1 teaspoon of lemon or lime juice in 1 cup of cold water (or 1/4 cup
lemon juice and 4 cups water), or use a commercial product like Ever-Fresh or Fruit-Fresh, available in most supermarkets. When
using one of these products, follow the manufacturer's instructions on the container.
Ascorbic acid or citric acid is simple vitamin C. It doesn't change the fruit flavor. It's sold in powder form and is usually found in drugstores.
- Vinegar, salt, and water: Make this solution with 2 tablespoons of vinegar (5 percent acidity), 2 tablespoons of salt (pickling or kosher), and 1 gallon of cold water. Don't leave the fruit in this solution longer than 20 minutes because the solution extract nutrients from the fruit and changes its flavor.
After dipping your fruit in the antioxidant solution you just rinse and drain it before packing into your prepared jars.