Composition of Foods

1
Composition of Foods
2
Composition of foods is important in

• Spoilage and desirable changes in
  foods
• Processing
• Preservation
• Nutritive value
• Organoleptic acceptance

3
Foods are generally water systems

• Dissolved water-soluble carbohydrates (mono-,
  disaccharides), proteins, fatty acids, mineral
  salts, vitamins, pigments, flavor compounds.
• Colloidal state most proteins, polysaccharides
• Emulsion fats

4
For survival, living entities need
to consume

• Hydrogen, carbon, oxygen, nitrogen, calcium,
  phosphorus, sulfur, sodium, potassium, iron, and
  some minor elements

5
Typical plant and animal tissue compositions
6
Water ( largest constituent of most foods)

• Fruits and vegetables 80-95
• Meat 74
• Cheese 37
• Cereals 12-20

7
Functions of water in living
cells and tissues

• It is a continuous matrix which holds the various
  food constituents either in dissolved, in
  colloidal or in emulsion form.
• It is a reactant in the photosynthesis reaction
• It is necessary for hydration, dehydration and
  hydrolysis reactions.

8
Functions of water in living
cells and tissues

• Solvent properties of water are important for the
  existance of chemical reactions, breakdown
  reactions, reassimilation processes, ionization
  of chemical species.
• It serves in the transport of nutrients,
  metabolites and spent material into and out of
  the cells
• It takes part in many important biochemical
  reactions.
• It is necessary for the structural integrity of
  cells.