The basic components of food are carbohydrates, proteins, fats, vitamins, minerals, trace elements and water.
Carbohydrates are composed of carbon, hydrogen and oxygen. Its sources are cereals, sugars, tubers and roots. It supplies energy for growth and activity. Carbohydrates also helps to control the breakdown of protein. It is necessary for using fat as a source of energy. Carbohydrates protect the body from toxins. Glucose is the basic chemical that provides energy to the body.
Monosaccharide is simple carbohydrate.
E.g.: sugar, honey, jiggery.
Polysaccharides- starch e.g.: cereals, grain, vegetables, and fruits.
Simple carbohydrates- fruits like banana, apple, dates, figs, raisins, prunes etc.
Complex carbohydrates- e.g.: cereals, legumes and tubers.
Carbohydrate supplies 50 to 70% of the daily energy requirement. 1gm of carbohydrate supplies 4kcal of energy.
Proteins re composed of carbon, oxygen, nitrogen, hydrogen, and sulphur in varying amounts. Some proteins also contain phosphorous and iron. Proteins are made up of simpler substances called amino acids.
Out of 22 amino acids needed by human body, eight are essential. Thus proteins are the building blocks of amino acids, which area the body basic units.
Proteins are classified into simple, compound and derived.
During digestion, the proteins present in the food is converted into amino acids and absorbed from the intestine. But once the body requires, the amino acids are grouped together in the body to proteins.
e.g.: milk, nuts, pulses, oil seeds.
Proteins are good for the growth of infants and children. Its highly essential for repairing the various tissues of the body, it helps in milk secretion.1gm of protein gives about 4kcal of energy.
Fats are composed of carbon, hydrogen and oxygen. It do have fatty acids too. Its sources are mainly of animal origin, e.g.: ghee, butter, fish oil: vegetable sources are groundnut, mustard, cottonseed, sunflower, coconut oil etc. the upper limit of fat intake is generally fixed at 30%of the energy intake. Excess of fat deposited in the body’s adipose tissue leads to overweight and obesity.
Fats are greasy in nature, soluble in fat solvents like alcohol. Classification of fats, include-
[A] (a)Simple fats- fatty acids and glycerol;
(b) Compound fats- e.g. phospholipids, spingolipids, mucoproteins;
(c) Derived fats- e.g.: cholesterol, sterol, Saturated fatty acids do have single bond and unsaturated fatty acids have double bond.
[B] (a) Saturated fatty acids- mutton fat, beef fat, palm oil, stearic acid etc.
(b) Unsaturated fatty acids- e.g.: olive oil, corn oil, soya been oil, etc.
Coconut oil - (saturated fat) – 92 (ply unsaturated fat)-2
Palm oil- (s.f) - 46 (p.f) – 10
Groundnut oil (s.f) – 19 (p.f) – 31
Cotton seed oil (s.f) - 25 (p.f) – 50
Sunflower oil (s.f) – 10 (p.f) – 75
Soya bean oil (s.f) – 14 (p.f) – 62
Essential fatty acids:
Most important fatty acid is linoleic acid, which act as the source for the production of other polyunsaturated acids. Other essential fatty acids are arachidonic acid, linolenic acid. I can give you the sources of arachidonic acids and linolenic acids
First we will deal about a few sources of arachidonic acid-
e.g. –meat, egg, contains 0.05 to 0.3%.
Milk- 0.4 to 0.6%
The sources of linolenic acid-
e.g.: – soya bean oil- 51%
Corn oil- 2% sesame oil- 40%
Mustard oil- 50%
Groundnut oil- 39%
Palm oil- 9%
Next classification of fats is
(a) visible fats and
(b) invisible fats
Visible fats are those visible to naked eye, e.g. – butter
Invisible fats are those which are not able to be seen, with naked yes. For e.g. fat present in oil, fat present in milk.
Properties of fats, we will also discuss about certain terminologies associated with fat, life randicity, sapponification iodine time. Etc…
First, we will talk about properties of fats, in short.
- Greasy to touch
- Insoluble in water
- But soluble in alcohol, ether etc.
- Fats on exposure becomes acidic
- Can be found in solid and liquid forms, that is, as fat and oil.
- definite melting point 49.3 degree Celsius- Bee wax
- fat has got reduced specific gravity, so floats over water
- specific gravity of solid fat is 0.86, that of liquid is 0.91 to 0.95
- Fats can spread uniformly over water
- Iodine time: grams of iodine absorbed by 100 grams of fat.
- Emulsification: fats are insoluble in water, but can be broken down to small droplets
- Hydrolysis of fat yields fatty acids and glycerol.
- Sapponification is the number of milligrams of potassium hydroxide, which is sapponified by fats. Unsaturated fatty acids react with ozone or oxygen that is auto oxidation, yields oxonides, peroxides, aldehydes, and ketones.
- Rancidity is development of flavors in fat
- Functions of fat-
- Fat considered as a constant source of energy, 100 grams gives 9.1 kcal.
- Essential fatty acids are needed for normal health.
- Fats are essential for adsorption of fat soluble vitamins like A, D, E, K.
- It can help to reduce the bulk of food, just like fibers absorb water.
- It can give feeling of fullness in stomach.
- It can increase palatability or taste of food.
- Phospholipids are essential for formation of neurons.
- Fat is deposited in adipose tissue and cab be utilized, when body is exhausted.
Vitamins are complex chemical substances, which act as catalyst in various body processes. Since body cannot manufacture them, these are supplied through the diet. Vitamins are essential for maintaining good health.
They are vitamin A, D, C,E, K,C, B1, B2, B6, B12, Niacin and Folic acid.
The term mineral is generally given to a substance, mined from the ground. Man gets minerals from the plants directly, or from animals that had previously eaten the plants.
There are Macro minerals that are required in comparatively large quantities, than Trace elements that are required in micro quantities.
Macro minerals are Calcium, Phosphorous, Sodium, Chlorine, Potassium, Sulphur, Magnesium, Arsenic and Manganese.
14 trace elements are there, e.g. Iron, Fluorine, Zinc, Copper, Cobalt, Molybdenum, etc.
Now that you have come across the various components of food, you may need to look at the best meal plan for you