Home | Basic knowledge of important nutrients

Chapter: 11th 12th std standard Home Science Maintain Basic Knowledge for family life Higher secondary school College

Basic knowledge of important nutrients

utrients are the constituents in food that must be supplied to the body in suitable amounts. These include carbohydrates, fats, proteins, minerals and vitamins

BASIC KNOWLEDGE OF IMPORTANT NUTRIENTS

 

Nutrients are the constituents in food that must be supplied to the body in suitable amounts. These include carbohydrates, fats, proteins, minerals and vitamins.

 

CARBOHYDRATES

 

Carbohydrates are sugars or polymers of sugars such as starch, that can be hydrolyzed to simple sugars by the action of digestive enzymes or by heating with dilute acids.

 

Carbohydrates are classified as monosaccharides or simple sugars (glucose, fructose), disaccharides or double sugars (sucrose, lactose) and polysaccharides which include many molecules of simple sugars (starches, dextrins).

Functions

 

The body uses carbohydrate as a source of energy. One gm of carbohydrate provides 4 kilocalories.

 

They are the major source of energy for muscular work.

 

The main source of energy for the central nervous system is glucose.

 

The body mainly uses carbohydrate as the source of energy, thus sparing the tissue protein breakdown for energy purpose. This is called 'protein sparing action of carbohydrates'.

 

In the liver, carbohydrates have special functions to perform. They include detoxifying action and a regulating influence on protein and fat metabolism.

 

The heart muscle mainly uses glucose as a source of energy.

 

Excess of calories is stored in the form of fat in the adipose tissue.

 

Consumption of indigestible polysaccharides or fibre prevents constipation and reduces the incidence of heart diseases, diabetes mellitus and colon cancer.

 

FOODS CARBOHYDRATE %

 

RICH SOURCES        

Sugar, jaggery,     85 - 99

Cereals and millets         63 - 79

Dried fruits 67 - 77

GOOD SOURCES      

Pulses         56 - 60

Milk powder , full fat     38 - 39

Milk powder, skimmed  54 - 55

Roots and tubers  22 - 39

FAIR SOURCES         

Fresh fruits 10 - 25

Milk  4

Nuts and oil seeds          10 - 25

 

 

 

FATS

 

The term lipid or fat is applied to a group of naturally occurring substances characterised by their insolubility in water. The lipids present in the diet of animal and human body includes triglycerides, phospholipids and cholesterol.

Functions

 

Fats are a concentrated source of energy. One gram of fat provides 9 calories.

 

Fat is essential for the absorption of fat soluble vitamins like vitamin A, D, E and K.

 

Fats improve the palatability and gives a satiety value (ie) feeling of fullness in the stomach.

 

Fats are deposited in adipose tissue and thus serve as a reserve source of energy during starvation and illness.

 

They protect vital organs in the body by forming a lining on top.

They act as insulators against heat and cold.

 

They are the essential constituent of the membrane of every cell.

 

Phospholipids are present in the plasma in combination with proteins as lipoproteins which are involved in the transport of fat and cholesterol.

 

Phospholipids are present in large amounts in the nervous system and essential for its function.

 

Cholesterol serves as a precursor for the formation of bile acids.

 

FOOD                  FAT%

 

RICH SOURCES          

Pure oils and fats           100

Ghee and vanaspathi               100

Butter                   80-81

GOOD SOURCES                 

Nuts and oil seeds                   40-60

Milk powder, fullfat                26

Eggs            14

Meat and fish                 10-15

 

FAIR SOURCES         

Milk, cow's 4

Milk, buffalo        7

Pulses (whole)      3-5

Cereals and millets         2-3

 

PROTEINS

 

Dietary protein performs all three functions of nutrients .It is needed for growth, maintenance, and repair of body tissues. It regulates key processes within the body and only excess protein can be used as a source of energy.

Functions

1 .  Proteins are required for the growth and maintenance of tissues.

It is needed for the formation of essential body compounds.

It regulates water balance in the body.

It helps in the transport of nutrients.

It is required for the maintenance of appropriate pH.

 

It is also a source of energy. One gram of protein provides 4 calories.

 

It fights the body against diseases.

It helps in detoxifying action.

 

FOODS      PROTEIN%

RICH SOURCES        

Meat, fish and liver        18-20

Eggs  14

Milk powder, full fat      26

Cheese        18-20

Pulses, dry  18-24

Nuts and oilseeds 18-26

Soyabean    35-40

GOOD SOURCES      

Cereals and millets         6-12

 

MINERALS

1. CALCIUM

 

Calcium makes up between 1.5-2% of body weight. Almost 99% of this calcium is found in the hard tissues of the body, namely the bones and teeth.

Functions

It is essential for the formation of bones and teeth.

 

It is essential for clotting of blood.

 

It regulates the permeability of capillary walls.


It is essential for the contraction of heart and muscle.

 

It regulates the excitability of nerve fibres and nerve centres.

 

 

It acts as an activator for the enzymes present in the gastric juice.

Food stuffs          Calcium (mg/100g)

Rich sources       

Milk powder, sesame seeds with       1.20-1.45

husk and small dried fish       

Good sources      

Ragi, milk   and green leafy    

vegetables and small fish eaten        

with bone             0.10-0.33

2. PHOSPHORUS

 

Phosphorus constitutes approximately 1% of the weight of the human body, Upto 90% of this is found within calcium phosphate crystals in the bones and teeth.

Functions

It is necessary for the formation of bones and teeth.

It is essential for carbohydrate metabolism.

It is a constituent of certain co-enzymes. 

It is an essential constituent of nucleic acids and nucleoproteins which are integral parts of the cell nuclei.

 

      Sources of Phosphorus

Food stuffs          Phosphorus (g/100g)

Cereals, Millets, Pulses, nuts  

and Oilseeds                  0.20 - 0.65

Dried fish             1.2 - 1.3

Milk powder                  0.76 - 0.82

Meat, fish and eggs                  0.31 - 0.41

Milk            0.09 - 0.11


3. IRON

 

Most of the iron in the body is found in the blood, but some is present in every cell bound to iron containing enzymes.

Functions

 

It is required for the transport and storage of oxygen in cells & tissues.

 

It acts as co-factors of enzymes and other proteins.

It is required for the formation of red blood cells.

Sources of iron

Food stuffs Iron (mg/l00g)

Rich sources                 

Sesame seeds, jaggery and               

green leafy vegetables.   10-20

Good sources                

Cereals and millets         3-8   

Liver 7-9   

Meat and egg        2-3   


IODINE

Functions

 

Iodine is a constituent of thyroxine, the active principle of the thyroid gland. The thyroid gland plays an important role in energy metabolism and in the growth of the body.

Sources

 

Iodine is present only in small amounts in common foods, the quantity of iodine present depending on the iodine content of the soil. Iodised salt and seafish are good sources of iodine.

 

VITAMINS

 

Vitamins may be defined as organic compounds occurring in small quantities in the different natural foods and necessary for the growth and maintenance of good health in human beings.


FAT SOLUBLE VITAMINS

VITAMIN A

Functions

Vitamin A plays a critical role in vision in dim light.

 

Vitamin A is essential for the integrity of the mucous secreting cells of epithelial tissues.

 

It is essential for normal bone formation.

Vitamin A deficiency causes degeneration of the myelin sheath.

 

Vitamin A is essential for the synthesis of mucoproteins and glycoproteins.

 

It is essential for normal reproduction.

Sources

 

Vitamin A is present only in foods of animal origin, such as liver, eggs, milk and fatty fish. All plant foods contain only carotenoids which is converted to vitamin A in the body .Papaya, mango, carrots, green leafy vegetables and other yellow, orange coloured fruits and vegetables are good sources of b-carotene.


VITAMIN D

Functions

 

Vitamin D promotes the absorption of calcium and phosphate from the small intestines.

This also acts on the bones directly promoting calcification.

It regulates the concentration of calcium in blood plasma.

Sources

 

The good sources of vitamin D includes sunlight, fish liver oils, butter, cheese, ghee and milk.


VITAMIN E

Functions

It is essential for normal reproduction in man.

It is required for the normal functioning of the immune system.

It is an antioxidant, which reduces the incidence of heart diseases.

Sources

 

Vegetable oils and fats, nuts and oilseeds and whole grams are the richest natural sources of vitamin E.


VITAMIN K

Functions

 

Vitamin K is essential for blood coagulation. It is required for the synthesis of various substances needed for blood clotting.

Sources

 

The concentration of vitamin K is highest in dark green leafy vegetables, but it is also found in liver, pulses, cereals and some tubers.


II. WATER SOLUBLE VITAMINS.

VITAMIN C OR ASCORBIC ACID

Functions

Vitamin C is essential for

Formation of collagens and intercellular cement substances.

Absorption of iron and incorporation of plasma iron in ferritin.

Bone formation.

 

Adrenal cortex function.

 

Neuro transmitter synthesis.

Aids in calcium absorption.

Drug detoxification.

 

Activation of hormones.

Sources

 

The rich sources of vitamin C includes amla, guava and other citrus fruits. Good sources include green leafy vegetables and fruits like papaya and tomato.


B Complex Vitamins

 

THIAMINE OR VITAMIN B1 FUNCTIONS

Thiamine is essential for growth.

 

It is essential for maintaining the nerves in normal condition.

It plays an important role in carbohydrate metabolism.

Sources

 

Diets based on whole wheat, millets, raw hand pounded rice or parboiled rice usually supplies thiamine in the diet. Organ meats, pork, liver, eggs and whole grams are fair sources of thiamine.

 

RIBOFLAVIN OR VITAMIN B2 FUNCTIONS

 

Riboflavin is involved in the regulatory functions of some hormones involved in carbohydrate metabolism.

 

The retina contains free riboflavin, which is converted by light to a compound involved in stimulation of the optic nerve.

 

Riboflavin plays, an important role in many enzyme systems involved in the metabolism of carbohydrates, fats and proteins.

 

It is involved in the formation of red blood cells in the bone marrow.

Sources

 

Rich sources of riboflavin include milk and milk products, eggs, liver, and dried yeast. Good sources are green leafy vegetables, whole cereals and millets, meat and fish. Fair sources include milled cereals, cereal products and roots and tubers.


NIACIN OR NICOTINIC ACID

 

Nicotinic acid is essential for the normal functioning of the skin, intestinal tract and the nervous system.

 

Nicotinic acid is a component of two coenzymes NAD and NADP, which take part in several enzymatic reactions.

Sources

 

The rich sources of niacin are groundnuts, dried yeast and liver. Good sources are whole cereals, legumes, meat and fish. The fair sources include milled cereals, maize, milk and eggs.


PYRIDOXINE OR VITAMIN B6

Functions

Pyridoxine like other vitamins functions as a co-enzyme.

 

It is essential for growth of infants and prevention of macrocytic anemia.


Sources

 

Meat, pulses,wheat and dried yeast are good sources while green leafy vegetables and other cereals are fair sources of this vitamin.


FOLIC ACID

Functions

It is essential for the maturation of red blood cells.

It is required for the normal growth and division of all cells.

It plays a role in the metabolism of some amino acids. 

It prevents megaloblastic anaemia.


Sources

 

Fresh green leafy vegetables, yeast, liver and eggs are rich sources of this vitamin. Cereals, pulses, nuts, oilseeds and other vegetables like ladies finger and cluster beans are good sources of this vitamin.


VITAMIN B12

Functions

It promotes the maturation of erythroid cells. 

It is involved in biochemical-processes essential for DNA synthesis and division of cells. 

It is required for the synthesis of myelin, the white sheath that covers the nerve fibers.

It stimulates appetite and improves the general health of the patient.

It cures the neurological symptoms of pernicious anemia.

Sources

Vitamin B(12)   is normally present only in animal foods like liver, egg,


mutton and milk.


PANTOTHENIC ACID.

Functions

It is involved in the synthesis of amino acids, B12 and hemoglobin.

Sources 

The best sources of pantothenic acid are liver, kidney, egg yolk, yeast and fresh vegetables. Milk and meat are fairly good sources.


BIOTIN

Functions

 

Biotin takes part as a coenzyme in several metabolic functions of carbohydrate and lipid metabolism.

Sources

 

Liver, kidney and yeast extracts are good sources. Pulses, nuts and chocolate are fair sources of this vitamin.


Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail
11th 12th std standard Home Science Maintain Basic Knowledge for family life Higher secondary school College : Basic knowledge of important nutrients |


Privacy Policy, Terms and Conditions, DMCA Policy and Compliant

Copyright © 2018-2024 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.