Most Common Food Preservation Methods
There are a number of methods to destroy and inactivate bacteria and enzymes that are responsible for spoiling food which results in shortage of food when it is a primary necessity.
This scenario is often experienced when you are going outdoors and pack food for a day or two. However, this can be avoided with simple food preservation methods. Here are 5 of them.
Canning is actually sterilizing the foods to ensure that any enzymes and micro-organisms are completely destroyed. In this method, the food is heated in sealed cans. Factors like acidity of a particular fruit or vegetable determines the degree of heat treatment required for this type of preservation.
This is another method of preservation mostly used to preserve foods like bacon and ham but fish is also preserved using this method in many parts of the world. In this method, salt is added to food and it withdraws water from food to control the growth of bacteria. In some cases, the food is placed in a smoke house after curing as it gives a characteristic flavor and color to the food.
In this method, the moisture content of the food is decreased by dehydration. When the water level in food becomes too low, it becomes difficult for micro-organisms to survive. Spray drying is one of the methods used for dehydrating foods. This method also has another advantage as the food becomes light-weight and further reduces transportation costs during distribution.
In this method, food is frozen below -5°C as the growth of bacteria and other micro-organisms doesn’t happen at this temperature. Almost any food can be stored indefinitely at deep-frozen temperatures of -20°C by inactivating the enzymes by blanching prior to freezing. Freezing does not destroy the bacteria completely and once the food is thawed they will begin to multiply again.
This is the process of soaking food in an acid solution such as vinegar. The acetic acid present inside the solution helps in limiting the growth of bacteria rather than destroying them as opposed to general thought. Most of the pickles are pasteurized because some bacteria such as a type of yeast can tolerate even the acid in vinegar). Many vegetables including onions, beetroot and cucumbers are preserved using this method.