food

 Chemical Composition of Food

Food is a complex mixture of water, proteins, lipids, and carbohydrates, which make various intra and intermolecular interactions in the texture.

The chemical composition of foods is usually made from a variety of chemical components. In addition, food is always prone to structural modifications during storage or processing. Analysis and quantification of food components is required to determine nutritional value and quality assurance of food products.

Foods are edible fragments of plant or animal organisms in a natural or processed state, which after being eaten and digested in the human, organism, may be a source of different nutrients . Taking as a base the dominant nutritional component, food products may be divided into four groups:

1. Protein food products

2. Saccharide food products

3. Edible fats

4. Fruits and vegetables

Example: Chemical composition of cereals(in %)

Water - 12 to 14

Carbohydrates - 65 to 75

Lipids - 2 to 6

Proteins - 7 to 12

 Eg of Cereals : Wheat, Rice, Oats, Maize, Barley etc.

METHODS OF FOOD PRESERVATION

The chief methods of food preservation are as follows:

1. Asepsis, or keeping out microorganisms.

2. Removal of microorganisms.

3. Maintenance of anaerobic conditions,

e.g., in a sealed, evacuated container.

4. Use of high temperatures.

5. Use of low temperatures.

6. Drying; this includes the tying up of water by solutes, hydrophilic colloids etc

7. Use of chemical preservatives, either developed by microorganisms or added.

8. Irradiation.

9. Mechanical destruction of microorganisms,

e.g., by grinding, high pressures, etc. (not used industrially)

10. Modified Atmosphere.

11.Combinations of two or more of the above methods