Home canned foods should have a bright color, characteristic texture,
pleasant flavor and contain nutrients naturally present. When all steps
of scientifically based canning directions are carefully followed,
color, texture and flavor will be optimum. These observable signs of
quality are also an index to nutrient retention of that canned food.
Proper pretreatment of the fruit or vegetable being canned is essential
for top quality. This includes using only good, wholesome food at peak
eating quality. Any trace of moldy or otherwise spoiled food should be
completely removed. All food must be washed thoroughly.
Removal of skins from thin-skinned foods such as tomatoes and peaches is
important. A short blanching time in boiling water loosens the skins,
and a short cooling time in cold or ice water stops the cooking of the
food. Because water leaches out vitamins, dilutes color and flavor, and
results in a mushy product, do not allow foods to soak unnecessarily in
either hot or cold water.
Air is an enemy of light-colored foods, and should be kept from the
peeled or cut food. This can be done with a commercial antioxidant
(ascorbic acid), lemon juice, or a simple solution of two tablespoons
each of vinegar and salt per gallon of water. Peel or cut food directly
into such a solution for maximum protection from air. When enough food
for a canner load is prepared, drain and rinse the food for best flavor.
The packing method used is one of the most important factors in quality
canned products. Foods that are heated before being put in jars have
better quality than foods packed raw in jars. Heating destroys enzymes
and removes much of the air from food tissues.
Enzymes must be destroyed quickly for top-quality food. Removal of air
not only shrinks the food, but leads to better color, flavor and
nutrient retention, and too, fruits are less likely to float. Hot packed
jars also have higher vacuums, thus less oxidation can take place.
Tomatoes and tomato juice are less likely to separate if tomatoes are
cut and heated at once. Cutting activates enzymes in tomatoes which then
change the pectins in the tomatoes and causes separation. Heating right
after cutting inactivates the enzymes and minimizes separation.
Sugar, salt and vinegar play important roles in quality canned foods.
While sugar is not needed to safely can fruits, it contributes to better
color, flavor and texture. Likewise, vegetables may be safely canned
without salt, but when salt is used, better flavor results. Salt is
essential for slow process pickles; vinegar is needed for quick process
pickles. Canning or pickling salt should always be used. Iodized salt
will inhibit proper fermentation and react with the starch in some
foods, causing them to turn pink or blue.
Sugar concentration in sirups is important to appearance of the fruit.
With a light sirup, fruits are less likely to float than with a heavier
sirup. And with a light sirup, fewer calories are added. Then too, the
cost is less than with a medium or heavy sirup.