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What is Food Preservation? – Definition, Importance, Objective, Methods

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It can be defined as the process in which we treat and handle the food to slow or stop the spoilage, its loss of nutritional value, quantity, and edibility of food items. Food preservation allows us to store food for a longer time. Preservation usually involves the prevention of the growth of fungi (such as yeasts), bacteria, and other microorganisms. This food preservation is used for various food products such as fruits, vegetables, meat, and fish by applying methods of salting, drying, etc.

Importance of Food Preservation

There is numerous importance of food preservation few of them are :

  • It increases the food shelf life.
  • It allows us to taste a variety of food products in any season and in any area.
  • It reduced the wastage of food items.
  • In food preservation, there is no change in the taste, color, and nutritional value of food.
  • Food products can be stored easily.

Objectives of Food Preservation

  • To prevent the growth of micro-organisms.
  • To minimize the spoilage of food items.
  • To protect the taste, color, and nutritional value of food products.

Methods of Food Preservation

 

There are two methods of food preservation :

  • Physical method
  • Chemical method

Physical Method 

Includes freezing, refrigeration, canning and dehydration, salting, fermentation, controlled atmosphere storage, vacuum packaging, modified atmosphere packaging, various forms of heat treatment, ionizing radiation, ultraviolet radiation, and high hydrostatic pressure.

Freezing

This is the modern version of food preservation. This process doesn’t kill the bacteria and yeast, this process just slows down the spoilage in the food. As yeast and bacteria both grow rapidly at a specific temperature (40F-140F), but lowering the temperature below 40F their reproductive and metabolic actions slow down. Food items such as sliced vegetables, berries, carrots, peas, and many more are preserved by this method.

Drying

Also known as dehydration. It is an ancient method used for food preservation. In these food items are dried the number of water decreases and as a result, it stops bacterial growth. The drying process can be done by bed dryers, shelf dryers, household ovens, fluidized bed dryers, freeze-drying, spray drying, and commercial food dehydrators. In this method, the weight of food products becomes lighter which makes products transportable. Food items such as fruits, vegetables, mushrooms, meats, and many more are preserved by this method.

Salting

It is the oldest method used for food preservation. In this method, salt removes the moisture from food and make an unfavorable environment for micro-organisms. There are very few bacteria that survive this excess high salt condition. This method can be used with other methods (dehydration, acidic solution) too. Food items such as vegetables, some fruits, fish, meats, and many more are preserved by this method.

Canning

This method becomes popular with the industrial revolution. In this method, food is preserved by removing the oxygen that is a basic need of micro-organisms. But still, some organisms can grow in absence of oxygen, so this method can be used with other methods (salting or with acid ). Food items such as jams, juices, vegetables, fruits, and many more are preserved by this method.

Fermentation

This method is done under anaerobic conditions which involve a chemical change in food that use organic acids to convert micro-organisms. These anaerobic conditions occur in the absence of oxygen. This environment stimulates a microbial conversion of starches and sugars into alcohol, which is already a natural preservative. Food items such as cheese, yogurt, and many more can be preserved by this method.

Vacuum Packing

This is done by food vacuum machines. In this method, food items are packed in a bag and then removed all the air present in that bag, and then seal it tight. This method increases the shelf life of food items. Food items such as cereals, nuts, cheese, coffee, and many more can be preserved by this method.

Ionizing Radiation

Irradiation is used for eliminating parasites, reducing pathogenic bacteria, and extending the shelf life cycle of food items. In this method, food undergoes the exposal of ionizing energy which suppresses microbial growth. Food items such as fruits, vegetables, spices, and many more can be preserved by this method.

Chemicals Method

Include food preservatives or antimicrobials, although benzoates, propionates, and sorbates.

Chemical Preservation

Modern industries are adopting the use of chemical preservatives. There are 3 types of chemical preservatives used for food preservation. Benzoates (such as sodium benzoate), sulfites (such as Sulphur dioxide), and nitrites(such as sodium nitrite). Before adding any chemical preservative, food goes through various processes like irradiation, cooking, and pasteurization in which ionizing radiations, heat, and high energy which kill bacteria and fungi that increase the shelf life of food. Food items such as cereals, jams, meat, juices, and many more can be preserved by these chemical preservatives.  

Conceptual Questions

Question 1: Name the chemicals used for food preservation? 

Answer: 

There are numerous chemicals used for food preservation, a few of them are-Sodium benzoate, Sulphur dioxide, Sodium nitrite, Sodium diacetate, Sodium lactate, sulfite, and Dehydroacetic acid.

Question 2. Write a brief note on Food preservation and its method?

Answer: 

Food preservation can be defined as the process in which we handle and treat food items to stop or slow down the spoilage and loss of quantity, nutritional value, and edibility. Food preservation makes food shelf life increase. Food preservation inhibits the growth of fungi, bacteria, and other micro-organisms. There are 2 methods of food preservation :

Physical method– freezing, salting, drying, canning, ionizing radiation,  vacuum packing, fermentation, etc.

Chemical method-use of chemicals for food preservation. Chemicals used are benzoates(such as sodium benzoate), sulfites (such as Sulphur dioxide), and nitrites(such as sodium nitrite). 

Question 3. Write at least 3 importance of food preservation ?

Answer:

Importance of food preservation :

  • Increases shelf life of cycles. 
  • It makes us enable to taste food in any season and in any area. 
  • Food wastage is reduced. 

Question 4. What are the advantages of the drying food preserving method ?

Answer:

Advantages of drying food preserving method 

  • It stops bacterial growth. 
  • It makes food items lighter and makes food easily transportable. 
  • It increased the shelf time of food products. 

Question 5. Explain the Salting method of food preservation ?

Answer:

It is the oldest method used for food preservation. In this method, salt removes the moisture from food and make an unfavorable environment for micro-organisms. There are very few bacteria that survive this excess high salt condition. This method can be used with other methods (dehydration, acidic solution) too. Food items such as vegetables, some fruits, fish, meats, and many more are preserved by this method.

Question 6: Explain the Fermentation method of food preservation?

Answer:

This method is done under anaerobic conditions which involve a chemical change in food that use organic acids to convert micro-organisms. These anaerobic conditions occur in the absence of oxygen. This environment stimulates a microbial conversion of starches and sugars into alcohol, which is already a natural preservative. Food items such as cheese, yogurt, and many more can be preserved by this method.


Last Updated : 03 Jul, 2022
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