describe the principle on which the following methods of food preservation are based :
a) boiling
b) canning
c) freezing
d) dehydrations
describe the principle on which the following methods of food preservation are based :
a) boiling
b) canning
c) freezing
d) dehydrations
Boiling: Boiling increases the temperature of the food in such extent that all microorganisms die.
Freezing: The food can be kept in frozen condition inside the freezer for a long time. The temperature inside the freezer is very low (lower than the freezing point). We know that usually microbes cannot grow in extreme conditions. For this reason by keeping food inside the freezer growth of microorganisms can be avoided. Without microbes the food materials remain fresh for a long time.
Canning: Food materials like fruits, vegetables, fishes etc. are boiled in sugar syrup or canning salt solution and are packed inside a can. Then the can is boiled in water bath or pressure canning is done for sterilization. Due to boiling in high temperature all microorganisms will die and airtight packing will prevent new microorganisms from entering in side.
Dehydration: The moisture of the fruits are taken out by drying them in sun or drier and then stored. As moisture is absent bacteria fail to grow there.
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Boiling: Boiling increases the temperature of the food in such extent that all microorganisms die.
Freezing: The food can be kept in frozen condition inside the freezer for a long time. The temperature inside the freezer is very low (lower than the freezing point). We know that usually microbes cannot grow in extreme conditions. For this reason by keeping food inside the freezer growth of microorganisms can be avoided. Without microbes the food materials remain fresh for a long time.
Canning: Food materials like fruits, vegetables, fishes etc. are boiled in sugar syrup or canning salt solution and are packed inside a can. Then the can is boiled in water bath or pressure canning is done for sterilization. Due to boiling in high temperature all microorganisms will die and airtight packing will prevent new microorganisms from entering in side.
Dehydration: The moisture of the fruits are taken out by drying them in sun or drier and then stored. As moisture is absent bacteria fail to grow there.
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