Preservation of food using sugar
The important of food preservation is to increase the shelf life of
food as well as its supply. Although the freshness,
palatability and nutritive value may be altered with time
delay, perishable foods can be preserved to prevent spoilage and
made to be available throughout the year. In this way,
preservation helps to increase variety in our diet and makes it better
balanced.
Sugar by definition is a sweet crystalline or powdered substance, white
when pure, consisting of sucrose obtained mainly from sugar cane and
sugar beets. Sugar is used to make delicious foods, such as cookies,
chocolate and other candy.
The main use of sugar is the diet is as a sweetener and it is the only
one of the mono- and disaccharides which is consumed in relatively large
quantities. It is also used as a preservative.
Preservation with the use of honey or sugar was well known to the
earliest cultures. In northern climates that do not have enough sunlight
to successfully dry fruits, housewives learned to make preserves by
heating the fruit with sugar.
Moisture content and water activity affect the progress
of chemical and microbiological spoilage reactions in foods.
Reduction of water activity can be obtained by drying
or by adding water soluble substances, such as sugar to
jams. Sugar binds moisture and thus can preserve food by preventing the
growth of microorganisms if a high concentration (65% or above) is
used. Products such as jams and jellies are preserved by using sugar.
Bacterial growth is virtually impossible below a water activity
of 0.9, which helps during food preservation.
In ancient Greece quince was mixed with honey, dried somewhat and
packed tightly into jars. The Romans improved on the method by cooking
the quince and honey producing a solid texture. The three sugars most
commonly occurring in food are fructose, sucrose and lactose.
Sucrose is added to many baked goods primarily for reason of taste, it
is frequently also the crucial factor in their preservation.
Sucrose also functions of a preservative for other products such as
marzipan, nougat, chocolate and pralines.
Preservation of food using sugar
