Many times our cooked food is left so we keep it to eat in the next meal or when we go through hunger pangs. However, this food is prone to spoilage which might deteriorate the texture and taste of food. This situation can be unpleasant and dangerous at the same time as the food may upset the stomach, if consumed while the unconsumed food creates a lot of wastage. Thus, food preservation is necessary. Here are some techniques to preserve cooked food for a longer time:
Food products such as meat, fish, yogurt, fruits etc when dehydrated can stay for a longer period of time. Dehydration removes the air and moisture from food items and retards the growth of bacteria and microorganisms. So, these food items can be dehydrated by various methods such as sun drying, oven drying and also by freeze drying.
This is the simplest and the most effective way of preserving food. This reduces the growth of microorganisms as the temperature in the chambers is 4°C to 5°C. Food items can be preserved for 2-7 days in the refrigerators.
Preservation by chemical preservatives
Sodium benzoate and potassium metabisulphite are two chemicals that are used in food preservation. They prevent the growth of fungus. They create a layer of sulphur-dioxide in a limited amount which is harmful to the bacteria but not for us. However, while using these, you must ensure to add only 0.1 % concentration of these products.
Usage of spices and oils
Some spices such as cloves, aniseeds, asafoetida, omum, fenugreek seeds, etc, not only enhance the flavor of our dishes but also helps in preserving food. Oil is also good in food preservation. It forms a layer on top of foodstuff and checks the entrance of air. Since bacteria and other microorganisms require oxygen to breathe so they die in the absence of air. This is the reason why pickles can be preserved for years.
A temperature of -18°C to -40°C is created on deep freezers so that bacteria growth is retarded. The temperature converts moisture into crystals. In this way, cooked food can be preserved.
Salt and sugar
Food can be dipped into sugar syrup or ascorbic acid before freezing. This will prevent the blackening of food. NaCl or the common salt also helps in food preservation as it absorbs water thereby making the bacteria devoid of moisture.
Lemon, citric acid, tartaric acid, vinegar, glacial acetic acid, and other acids help in food preservation by providing an acidic medium which is unfavorable for the growth of fungus and bacteria. It also prevents the crystallization of food.
You can use cling foils for preserving all sorts of bread and rice
So the next time you have leftover food, just follow these simple techniques and save your money, energy and time.
Image Sources: TheHealthSite.com, Food Network Canada, Wikimedia Commons