Nutrition and Food technology

 Nutrition and Food technology

We eat food in order to obtain energy for the maintainance of life wnd also provide raw materials to build and repair the body. Thus there is a continuous need of food. Unfortunately, the food is seasonal and unform in the global. In order to ensure to continue supply of food some of it must be preserved and stored for later use.

           Food is destroyed either by the growth of micro-organisms such as bacteria, fungi due to the enzyme of the cells of food. Man knows since the ancient time, the methods to preserve the food but these methods were not effective in preserving food for longer time. The nutrientional value and taste were considerably lost in food through sich traditional methods.

               With the help of modern science various methods have been developed to preserve the food for the longer period of time without affecting its nutrientional value and taste.

1. Pasteurization:

It was discovered by louis pasteur to prevent the milk from turning sour you all know very well that is milk is boiled after purchasing it from milk-man. Increase in temperature of milk up to boiling point, kills most of the germs ( bacteria) present in it thus milk can be kept longer. It turns sour in the absence of boiling very quickly.The modern way of milk pasteurization comprises of heating to 71°C and then immediate cooling. As a result most of its bacteria are either killed or of survive, their growth is retarded so the milk can be preserved for few days

2. Refrigeration:

Refrigeration is an other way of preserving food. In this method food is kept at very low temperature at -30°C to -40°C. Due to very low temperature the bacteria are either killed or their growth is retarded. Now a days, food quickly freezez (-18°C) inabout 30 minutes. Taste and texture is remder in the food.

3. Dehydration:

It is oldest method of preserving food by dehydration. Although drying pf food does not kill micro-organisms, its preserves the food as it makes water unavailable micro-organisms which requires it to grow and multiply. Dried food is easily stored and transported due tonits light weight. However, it often brongs about a change in texture and taste of preserving food. 

4. Canning:

In this method food is adequately cooked and then sealed while hot in a sterile, metallic and air tight container. Heating kills the micro-organisms as well as inactivates the enzyme.