Characteristics of Food Nutrients
The various food nutrients differ from each other on their:
- Physical appearance: These include their structural appearances. The physical properties of a food may change when it is treated in certain ways.
- Chemical properties: The include the chemical compositions of the nutrients. This means the units or elements or groups of elements that make up the nutrients and how they behave under certain conditions.
Proteins are body builders. They are important for building and repairing of body tissues. Sources include meat, fish, eggs, poultry, milk, beans, etc.
Characteristics of protein:
1. Proteins are made up of carbon, hydrogen and nitrogen. These are elements. Some proteins also contain small amount of sulphur or other elements.
2. The elements arrange themselves in different combinations to form amino acids.
3. The amino acids then form the proteins.
4. The final products of protein digestion are the amino acids. Proteins are digested by enzymes called protease.
5. Most proteins are insoluble in water.
6. Many proteins are coagulated by heat.
7. Protein is not easily destroyed by heat.
Effects of am Heat on protein:
• place an edge gently sauce pan of boiling water.
• boil for 10 minutes.
• remove the egg.
• let it cool down, shell and cut it into two.
The White of the egg has solidified or "set". This effect of the heat on protein is known as coagulation. The same change takes place when meat, milk or fish is cooked.