Food Preservation - Definition, Importance and Methods

Food preservation is a smart method that has been employed since ancient times. Food is an essential requirement for living beings to exist. But food items perish very quickly. Our ancestors used basic items like salt and sugar to preserve food. Modern times use chemical methods and preservatives to lengthen the life of food items. Various techniques like Canning, Freezing, Drying, and Pickling are used to preserve and protect food. Microorganisms are responsible for spoiling the food. All these techniques make sure that the microorganisms are not allowed to grow.

Drying Food is the most ancient technique used for food preservation. Let us study more to understand the importance of preserving food and the different Methods of Food Preservation.

What is Food Preservation?

Defilement of the food by microorganisms prompts an adjustment to the variety and taste of the food. It is vital to embrace legitimate strategies for food protection. Food preservation is the method by which food is kept safe from microorganisms by employing different techniques. Microorganisms follow up on food things and ruin them. Microorganisms mostly include Bacteria and Fungi, which cause food to be spoiled. Certain synthetic substances restrain the development of microscopic organisms and increase the existence of prepared food.

Objectives of Food Preservation

Following are the objectives of preserving food:

1. The main aim is to prevent spoilage of food by microorganisms.
2. It also enhances the shelf life of food that tend to rot easily.
3. Food preservation also enhances and maintains the nutritional value of the food being preserved.
4. Any kind of contamination in food is prevented via Food preservation.
5. It also helps the country economically by minimising post harvest losses and allowing distribution of food to wider markets.
6. Food preservation also provides convenience in meal preparation as a lot of items are already in a semi-prepared state.

Importance of Food Preservation

The following points illustrate the importance of food preservation techniques:

1. Food preservation helps prevent the spoilage of food by slowing the oxidation of fats that result in rancidity.
2. Different preservation techniques allow the availability of a variety of food during different seasons.E.g. Canned Food, Frozen food, etc.
3. Food preservation allows more food to be supplied across the region.
4. Fruits like Pineapple and Cherries have a small shelf life. Preservation techniques help in elongating their shelf life.
5. Food preservation allows for a balanced diet to be followed since a lot of food items become available all around the year.

Common Methods of Food Preservation

There are several different techniques which are employed to preserve different kinds of food. The various techniques have been listed below:-

A. Chemical Method of Food Preservation

Synthetic additives are utilized in food conservation by significant food enterprises as they are innocuous to people. Sodium metabisulfite and Sodium benzoate are generally utilized substance additives. For the most part, salts and eatable oils are utilized to control their development, and these are named additives.

Corrosive additives are likewise added to keep food from decay in pickles, squashes, jams, canned food, and so forth. A few common additives are:

• Sodium chloride (salt) in Meat, Amla, crude mango, fish, and so on.
• Eatable Oils in a pickle, etc. 
• Sodium benzoate in Fruit juices, syrups, jams, and so on.
• Sodium metabisulfite in Dried organic products/vegetables, syrups, organic product juices, and so forth.

B. Physical Method of Food Preservation

Physical techniques which are used in food preservation include-

Pickling

Oil and vinegar keep an eye on deterioration in pickles. Vinegar has the property to pause and dial back the waste of food over an extensive stretch of time. This is generally utilized in making pickles.

By Common Salt

Vegetables are cured involving salt, as salt eliminates water and kills microscopic organisms and parasite cells. Common salt otherwise called sodium chloride is utilized as an additive at home. Consequently, salt is added to fish and meat to remove dampness content with the goal that microbial action is hindered.

By packing and storage

Dry leafy foods and vegetables are safeguarded in water/airproof/air-fixed holders. The shortfall of air forestalls the development of microbes or growths.Food ought to be put away in legitimately fixed parcels or impenetrable compartments. Organisms need dampness, air, and so on for development. Accordingly, such compartments would hinder their development.

Crystallisation

Fruits, such as Apples, Peaches, and Apricots, are kept for a long time with sugar either as fruit syrup or in a crystallized state, where the preserved substance is boiled in sugar until it crystallizes and is further stored in a dry medium. Ginger, angelica, and citrus peels are treated with this methodology.

Drying

In this technique, food items like vegetable and meat are kept in the Sun which allows the moisture to be removed from these items.

Salting

The moisture from meat can be removed via salting or curing. The rubbing of salt results in the water removal by the Osmosis process. Clostridium botulinum is commonly seen infecting meat which is inhibited by treating meat with nitrates and nitrites.

Canning

Canning is a food preservation method where the food is heated to a temperature that destroys microorganisms that cause spoilage. High heat also inactivates enzymes that can cause food to spoil. The food is then sealed in airtight containers, preventing new microorganisms from entering and spoiling.

Water-bath canning is utilized for high-acid foods, such as natural products, jams, jellies, pickles, and salsa. Water-bath canning includes warming the filled jars of food in bubbling water for a particular sum of time. Pressure canning is utilized for low-acid foods, such as vegetables, meats, fish, and dairy items. Pressure canning includes warming the filled containers of food in a pressure canner, which cooks the food at a higher temperature and pressure than water-bath canning.

Refrigeration

Refrigeration is one of the frequently used methods of food preservation. The term “refrigeration” comes from the Greek word meaning “cold” or “temperature.” Refrigeration involves keeping the food at a temperature commonly between 0°C to 4°C, (32°F to 39°F). A low temperature slows the growth of microorganisms, thus enhancing the life of the food materials.

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