Jam & Jelly
Fresh fruits contain more than 80 per cent water and 10 to 15 per cent sugars. Therefore,
fruits are good food for microorganisms. The fruits spoil very fast, if not preserved in time.
One of the traditional methods of preservation is conversion of fruit pulp to jam and jelly.
The preservation of fruit by addition of sugar helps in reducing water content required by
spoilage microorganisms. Jam, jelly and marmalade are based on preservation by high sugar
concentration. All fruits can be converted to jam by mashing or slicing it fine, adding an
approximately equal amount of sugar, and simmering until it reaches proper concentration or
gel at 218° to 222°F (103°–105°C). A process flow chart for jam making is given in Figure below.
The process of jelly making is also similar except that only fruit extract is used for making of
jelly and pectin is added for gel formation after boiling.