|
|
Dehydration:- The word Dehydration means removing water or moisture from foods.
The home method of Dehydration is sun drying.
Some foods are dried as they are eg. Green leafy vegetables (methi, phodina, corriander etc.),
cauliflower, grapes, amla, onion, raw mango etc.
Some foods are cooked and then dried eg. Potato chips, papad, banana chips etc.
The most appropriate wether to dry fooods is when the air is dry and there is strong sun shine.
Low temperature:-
Low temperature slows microbial and enzyme action. The food is thus prevented from spoilage.
Foods can be preserved at low temperature by:-
Refrigeration
Cold storage
Freezing
Out of the three methods , freezing uses the lowest temperature.
Increasing temperature:-
By Increasing the temperature, enzymes and microorganisms are destroyed, leaving the food safe from spoilage.
There are two methods of preserving foods by using high temperature:-
Pasteurization
Sterilization
Using natural preservatives:-
Salt
Increasing the quantity of salt in the food changes its composition due to
which microorganisms cannot survive. It also reduces the activity of enzymes,thus preventing the food from getting spoilt.
Salt is used as a presrvative in pickles, chatni, sauce, canned food.
It is also rubbed on fish which helps to preserve the fish.
Sugar
The sugar dissolves in the water available in the food item.
This results in the less water being available for growth of micro-organisms.
Sugar is used as a presrvative in jams, jellies, murabbas, squashes.
Acids
Acids increase the acid content of food items, thus preventing the activity and growth of micro-organisms.
Vinegar is used to preserve onions, tomato ketchup
Lemon juice is used in pickles
Citric acid is used in squashes
Oils and spices
Mustard powder prevents the growth of micro-organisms, thus preventing spoilage.
Oil acts as a cover on the pickle of mango, lemon and vegetable so that the micro-organisms
cannot come in contact with the food.
|
| Author: Mala R 08 Sep 2008 | Member Level: Bronze Points : 1 |
Your article is very interesting and knowledgable. We get to know more reading such nice things.
|
| Author: m.v. subba raju 08 Sep 2008 | Member Level: Gold Points : 2 |
Hi Lalitha,
Good article. Though everybody preserve the food items in refrigerators but they will not concentrate what are the benefits of it except food will not spoil the reason normally we will not bother. So, by reading articles like these we will get some idea. So keep on posting such good articles.
Subba Raju, MV
Member, IRC
|