Food preservation is the application of techniques to prevent or minimize undesirable changes in food.
Preservation aims either to destroy or inhibit the growth of harmful microorganisms in food by making an environment unsuitable for them.
From the nutrition viewpoint, food preservation is essential in improving the general health of the family by supplying it with a varied and balanced diet.
Food preservation assures the consumer of a supply of foods that are out of season.
Preserved food can be transported long distances from where it is produce and stored for long periods in warehouse or homes without risk of its decomposed or endangering health.
Food preservation involves the use of heat, cold, drying, (water activity or Aw), acid (pH), sugar and salt, smoke, atmosphere, chemicals, radiation and mechanical methods.
A methods of making food safer that us well known and accepted today is pasteurization.
Pasteurization is the process of heating foods to a temperature for a designated period of time to destroy disease-causing and/or food spoilage bacteria.
It is to reduced the number of harmful microorganism, of present, to a level at which they do not constitute a significant health hazard.
A newer form of pasteurization is called ultrahigh temperature (UHT) pasteurization.
The amount of bacteria killed a heat method such as pasteurization depends how high the temperature is, and how long the food is held at the low temperature for a long time.
But using very high heat means that the food can be kept at that heat for a shorter time.
Preservation techniques that limit the availability of water, such as drying, salting and smoking and those that use heat, such as canning and pasteurization, dramatically alter the nature of food itself.
High pressure processing is another technology gaining popularity in recent years wherein high pressure are used to inactivate microorganisms in foods.
There are are several methods of applying electricity instead of heat to a pasteurize food; these technique are referred to as cold pasteurization. Irradiation, ohmic heating and high intensity pulsed electric fields are some of these technologies.
Irradiation methods involve treatment with ionizing radiation – gamma rays, x-rays, ultraviolet radiation and microwaves.
Pulsed food processing technologies include pulsed electric fields, pulsed light fields, and pulsed magnetic field.
Food Preservation
