methods of Food preservation

 Food preservation is important to minimize the wastage.

We’ll learn about three commonly used methods of food preservation. Canning, freezing, or drying are the three techniques used for food preservation. These techniques can be used at home as well as for commercial purpose.

Canning:

Canning is a method of preserving food in which the food contents are processed and sealed in an airtight container. Shelf life of canned food can range from one to five years. In this process, heat is applied to food that’s sealed in a jar in order to destroy any microorganisms that can cause food spoilage. Proper canning techniques stop this spoilage by heating the food for a specific period of time and killing these unwanted microorganisms. During the canning process, air is driven from the jar and a vacuum is formed as the jar cools and seals.

The canning methods commonly used are water-bath canning and pressure canning:

• Water-bath canning: This method uses a large kettle of boiling water. Filled jars are submerged in the water and heated to an internal temperature of 200 Degrees Celsius for a specific period of time. This method is useful for items like high-acid foods, such as fruit, items made from fruit, pickles, pickled food, and tomatoes.
• Pressure canning: Pressure canning uses a large kettle that produces steam in a locked compartment. The filled jars in the kettle reach an internal temperature of 240 Degrees Celsius under a specific pressure on the pressure-canner cover. Use a pressure canner for processing vegetables and other low-acid foods, such as meat, poultry, and fish.

Pressure canner is different from a pressure cooker, which is used to cook food quickly. A pressure cooker does not have adequate room for both the canning jars and the water needed to create the right amount of pressure to preserve foods.

Freezing:

You can freeze most fresh vegetables and fruits, meats and fish, breads and cakes, and clear soups and casseroles. The keys to freezing food are to make sure it’s absolutely fresh, that you freeze it as quickly as possible, and that you keep it at a proper frozen temperature (0 degrees).

Properly packaging food in freezer paper or freezer containers prevents any deterioration in its quality. Damage occurs when your food comes in contact with the dry air of a freezer.

Important things to remember,

• Wrap food tightly.
• Keep the freezer closed as much as possible. Know what you want to remove before opening the door.
• Don’t overfill: An overly full freezer reduces air circulation and speeds freezer damage.
• Drying:
  Drying is one of the oldest methods known for preserving food. In this method, you expose the food to a temperature that’s high enough to remove the moisture but low enough that it doesn’t cook. Good air circulation assists in evenly drying the food.
  Electric dehydrator is the best and most efficient unit for drying, or dehydrating, food. Today’s units include a thermostat and fan to help regulate temperatures much better. Although sun drying is very cost effective, it takes longer time.