Food Preservation: Definition, Importance, and Methods

Food Preservation: Food provides energy to all of us. Food that is unhealthy or spoiled is the leading cause of disease in humans. This is referred to as food poisoning. To avoid this, food must be preserved in a variety of ways. Continue reading to learn about food preservation and the various methods of food preservation.

Food preservation is one method of protecting food from microbial growth. We store and protect the food after it is made by covering the rice and curry with lids to keep flies and other insects away. We are thus protecting it from any infection caused by them. This is a temporary condition. Food preservation, on the other hand, is done to keep food fresh for a longer period of time.

What is Food Preservation?

Food can undergo spoilage due to various factors, including contamination by microorganisms, infestation by insects, degradation by endogenous enzymes (those present naturally in the food) physical and chemical changes, such as the tearing of plant or animal tissues or the oxidation of certain constituents of food, may promote food spoilage that renders food unfit for human consumption. Therefore, foods are required to be preserved to stop or slow down food spoilage and longer food storage.

What is Food Spoilage?

Foods can be of plant or animal origin and it contains moisture, protein, lipid, carbohydrate, minerals, and other organic substances which are consumed for nutritional purposes. Food spoilage is simply defined as the original nutritional value, texture, flavour, odour or colour of the food that is damaged or changed so that the food becomes harmful to people and unsuitable to eat. The major bacteria related to food poisoning are Salmonella, Staphylococcus aureus, Bacillus cereus, Clostridium perfringens, Campylobacter, and Listeria monocytogenes.

Define Food Preservation – Reasons for Food Spoilage

1. Growth of microorganisms like bacteria, fungus etc., or insects.
2. Autolysis: Enzymes are proteins found in all plants and animals.
3. Oxidation by air causes rancidity or colour changes.
4. The changes occurred due to physical (freezing, burning, drying), chemical, biological and environmental factors.
5. Spoilage causes changes in organoleptic quality (smell, touch, taste, sight), nutritional value, and food safety.

Principle of Food Preservation

1. To prevent and remove microbial contamination.
2. To inhibit microbial growth.
3. To kill contaminating pathogens.
4. To minimize food spoilage, food infection and food poisoning.

What are the Methods of Food Preservation?

1. Drying: It is the ancient practice of food preservation. This methodology decreases water activity that stops bacterial growth. Drying decreases weight, so foods can be carried easily from one place to another. Sun and wind square measure each used for drying as well as advanced applications like bed dryers, fluidized bed dryers,ze-drying, shelf dryers, spray drying and commercial food dehydrators and household ovens. Meat and fruits like apples, apricots and grapes square measure some samples of drying with this methodology.

2. Freezing:zing is the method of keeping ready-made foodstuff in cold storage. Sweet potatoes can be stored in pitch black or unlightened rooms; however sweet potato preparations need to be frozen.

3. Smoking: Smoking is the procedure that cooks, flavours and preserves food exposing it to the smoke from burning wood. Smoke is antimicrobial and inhibitor, and most frequently, meats and fish square measure smoke-cured. Numerous ways of smoking a square measure used to like hot smoking, cold smoking, smoke preparation and smoke baking. Smoking as a preservative enhances the danger of cancer.

Fig: Smoking

4. Vacuum Packing: A vacuum by creating baggage and bottles airtight. Since there’s no chemical element within the created vacuum microorganism dies. They are sometimes used for dry fruit.

5. Salting and Pickling: Seasoning, collectively called natural process, removes wet from foods like meat. Pickling suggests that protective food in brine (salt solution) or marinating in vinegar (acetic acid) and in Asia, oil is employed to preserve foods. Salt kills and inhibits the expansion of microorganisms at \({\rm{20 \% }}\) of concentration. There are different techniques of picklings, like chemical pickling and fermentation pickling. In industrial pickles, sodium benzoate or EDTA is added to increase shelf life or extend the time period.

Fig: Salting and Pickling

6. Sugar: Sugar is used in syrup form to protect fruits or in the crystallized form; if the substance to be preserved or protected is cooked in the sugar till crystallization takes place like candied peel and ginger. Another use is for glazed fruit that gets a superficial coating of sugar syrup. Sugar is additionally used with alcohol to preserve luxury foods like fruit in strong drinks like brandy.

Fig: Sugar

7. Canning and bottling: During this methodology, the waterproofing broiled food in sterile bottles and cans. The instrumentality is cooked, and this kills or weakens microorganisms. Foods are cooked for numerous lengths of time. Once the will or bottle is opened, the food is once more in danger of spoilage.

8. Jellying: It is the strategy of protective food by preparation in an exceedingly material that solidifies to make a gel. Fruits are typically preserved as jelly, preserves or fruit preserves, and therefore the gelling agent is cellulose that’s naturally found in fruit. Sugar is also added.

9. Radiations: Ultraviolet radiation is high for decreasing surface contamination on various foods. This short-wavelength light has been used in the cold storage units of meat processing plants. Ionizing radiations such as gamma rays can be used to preserve certain types of vegetables, fruits, and spices, according to state and U.S. federal regulations.

10. Lyophilization: Freeze-drying is also known as lyophilization. It is an important method of storing biological, pharmaceutical and foods. The basic methodology of lyophilization is to remove the water or wet content from the foodstuff.

11. Sterilization: Sterilization is of various types such as steam sterilization, flash sterilization, low-temperature sterilization, etc. Sterilization is a simple process that removes all the bacteria, fungi, yeasts, moulds, etc., from contamination and allows storage of food at ambient temperature, thus increasing the shelf life of food.

12. Pasteurization: Pasteurization is a simple and mild heat treatment given for various packaged and non-packaged foods (such as milk and fruit juice) that kill most microorganisms. For example, milk under \(63\) degrees C, for \(30\) minutes. The pasteurized products are cooled after the heat treatment.

What is the Importance of Food Preservation?

1. Food preservation decreases food wastage and saves food from throwing into the wet waste.
2. It increases the storage period of food.
3. It makes it possible for us to get fruits and vegetables even in off-seasons. Nowadays, we get cauliflower, capsicum and apples throughout the year.
4. It makes it possible for us to get perishable food such as fruits and vegetables from far-off places. Apples of Kashmir and oranges of Nagpur are available in Delhi as well.
5. Food preservation prevents the food from being spoiled by the action of enzymes and microbial pathogens.
6. Food preservation retains the quality of food- colour, texture, flavour and nutritional value.

Food Preservation – Summary

We should always consume fresh food with no added preservatives to maintain good health. Few foods require food preservation like potato chips, and rice chips which are preserved by using old techniques like sun drying, preserving food using castor oils, etc.

Preservation by low-temperature techniques is superior to other methods of long term preservation because it is more effective in retaining the flavour, colour and nutritive value of food and moderately effective for the preservation of texture. It is comparatively a less time-consuming preservation method. There are other methods of preservation that involve advanced scientific techniques which can preserve food for longer periods.

FAQs on Food Preservation

Here we have provided frequently asked questions on Food Preservation:

Q.1. What is food preservation?
Ans: Food preservation is the process of treating food to stop or slow down spoilage, loss of quality, edibility, or nutritional value.

Q.2. What are the 5 methods of food preservation?
Ans: 1. Drying
2.zing
3. Smoking
4. Canning
5. Salting and Pickling

Q.3. What are the advantages of food preservation?
Ans: 1. It decreases food wastage and saves the food for future use.
2. It increases the storage period of food.
3. It makes it possible for us to get fruits and vegetables even in off-seasons. Nowadays, we get cauliflower, capsicum and apples throughout the year.

Q.4. What are the natural food preservatives?
Ans: Drying the food items under the sun, storing the foods in clay pots, preserving food using castor oil, etc., are few natural food preservatives.

Q.5. What foods have no preservatives?
Ans: Fresh foods like fruits, vegetables, milk, chicken, eggs, etc., do not have preservatives.