NUTRITION

Food is taken by an organism for growth work, repair maintaining life processes and body heat. Nutrition is the study of composition of food material and quantity of food required for proper growth. The main components of food are carbohydrate, proteins, vitamins, fat, minerals water and roughage.

Carbohydrate is a compound of carbon hydrogen and oxygen and is main source of energy. 01 gram of carbohydrates produces 4kcal of energy. There are three types of carbohydrate cellulose, starch and sugar. Cellulose constitutes the roughage and starch and sugar provide the energy. Main source of carbohydrates are wheat, rice and maze. Source of glucose is grapes and sucrose is cane sugar. If the iodine solution turns blue black in colour, the food shows presence of starch and, if the Benedict solution gives red precipitate presence of sugar is confirmed

Fats are esters of long chain of fatty acid and glycerol and provide twice as much energy as provided by same amount of carbohydrates. Main source of fat are butter, ghee, cheese & ground nut. If the fatty acid present is saturated, fat is solid at room temperature and if the fatty acid present is unsaturated, the fat is liquid at room temperature. The fatty acid which can not be synthesised in our body are called essential fatty acid i.e. Linoleic acid.

Protein are compound formed from amino acid and are very important for growth and repair of the body. Main source of protein are meat, fish, egg, ground nut and pulses. The test for protein is done by concentrated nitric acid. The food sample first turns yellow and when ammonium hydroxide solution is added is changes into orange.Some important protine are pepsin, trypsin, actin, myosinenzyme protine.

Our body needs some mineral for its proper functioning like Fe, Ca, Na , K & Ph

Vitamins are necessary for normal body function but they do not provide energy. Balanced diet is the diet in which all the nutrients are present in adequate amount.Eg. of vitimins : vitimin A, vitimin B, vitimin C, vitimin D, vitimin e, vitimin K.

Diseases, which are caused by lack of nutrients in our diet, are called deficiency diseases. Some important deficiency deseases are:

Protein energy deficiency disease or Protein energy malnutrition(PEM).
Minerals deficiency disease.
Vitamins deficiency disease.

Protein energy malnutrition effects the children of age group 1 to 5 years. The main diseases are Kwashiorkar and Marasmus. Kwashiorkar disease is because of lack of protein in the diet and Marasmus is because of deficiency of carbohydates fat and proteins

Deficiency of iron causes anemia, iodine causes Goitre, calcium causes Ostomalacia in adults and rickets in children.

Deficiency of: -

Vitamin A (Ratinol) causes night blindness. Source of vitamin is Cord liver oil,mango, carrot, papaya.
Vitamin B1 (Thiamine) causes Beri Beri. Source of vit is ground nut,pulses, milk & liver.
Vitamin B2 (Riboflabil) causes Ariboflavinosis. Source of vit milk & beans, liver.
Vitamin B4 (Naicin) causes Pellagra . source of vit ground nut, meat.
Vitamin C (Ascorbic acid) causes Scurvy. Source citrus food like Amla,oranges, lemon, guavas.

Excessive intake of vitamin causes hyper vitaminosis.

Obesity arises when person eats more food than it body can consume.

Contamination of food material by non-edible toxic substance is called food adulteration.

Vanaspati in Ghee Hydrochloric acid when added to the ghee with the pinch of salt gives deep red colour.Argemone Oil in edible oil to the oil sample concentrated nitric acid is added radish brown colour shows presence of adulterants. Metanil yellow in dalDrop of concentrated acid in dal water gives pink colour.
Roughage is required to maintain healthy digestive system.

Food Production
Organism which can synthesis their own food in presence of light carbon dioxide water are called autotrophs and organism which can not synthesis their own food are called hetrotrophs. Plants need minerals for their growths. Minerals required in large amount are macro-nutrients and minerals that are required in small number are called micro-nutrients.

To produce good harvest agricultural practices to be followed are: -

Preparation of soil (ploughing, levelling and manuring)
Sowing
Application of the fertilisers
Irrigation.
Control of weeds
Crop protection.
Crop improvement
Harvesting
Threshing
Winnowing

Alternation of crop in the same field is called crop rotation which improves the fertility of soils, saves nitrogen and helps in weed and pest control.

Manure are obtained from animal plants and human waste which supply essential elements and moisture to the soil. Fertlisers are organic compound synthesis in factories. When the organic matter increases in the soil it is washed out in the rivers and ponds this causes increase in amount of algae as a result there is lack of dissolve oxygen in water. This is called eutrophication.

Unwanted plants in the cultivated crops area are called weeds i.e. wild oat, grass and Amaranthus they are either removed by hand picking or by spraying 2,4-D, MCPA and Butachlor. The insects are controlled by pesticides like DDT, BHC Malathion and Zinc phasphite.

Different varieties of crops are interbreed to obtain desired characters. This process is called hybridization. HYV of wheat are Sonara-64, Sonalika and Arjun. Rice is Padma and Jaya and Maize is Deccan hybrid and Ganga -101. The high yielding variety of Mexican wheat caused green revolution in our country.

Domestication and rearing of animals for food clothing are studied under animal husbandry. Animals are to be provided with proper feed shelter drinking water and cure of diseases.

Some diseases are foot and mouth diseases (viral diseases) Cholera T.B. and Anthrax bacterial disease.

Breeding of animals is done to improve the variety by artificial insemination in which semen from desired male is injected into the genital tract of the selected female animal. The high yielding variety of cow is Sahiwal, Karan-fries, Kranswiss and Jersy.

Management of Food Resourses
To ensure the availability of food various steps are taken for production and storage. They are collectively known as management of food resources.

Planning for food production.
Monitoring the progress of food production plans.
Pre harvest and post harvest of crops.
Procurement of grains.
Safe storage of food grains.
Control of Pest and diseases in stored food grains
Processsing of food materials.
Preservation of perishable food.
Packing of food material.
Transportation of food material.
Distribution of food materials.
Conservation of food material.

The moisture content of food grain should not be more than 14% to ensure a safe storage. Weed seeds, straw, earth particles should be removed. Food grains be checked for insects and diseases.

Food material can be stored by dry and cold storage. The cold storage does not allow the micro organism to grow and prevent the action of enzyme on the food. During dry storage the pest can be controlled by using pesticides and fumigants like malathion, EDB, Aluminum Phosphide, Methyl Bromide and DDT.
Raw food materials are changed to readily usable form by food processing which includes Canning, Pasteurization, Quick Freezing, Freeze Drying & Sterilization.
The process in which the micro organisms responsible for food spoilage are killed are called Bacteriocidal methods and the process in which the growth of microbes are prevented are called Bacteriostatic methods.

The high concentration of sugar and salt prevents the growth of microorganisms because it has very little moisture available for the growth of the microbes. Deep freezing renders the enzymes inactive. The chemicals used for preservation are Benzoic acid ( Sodium Benzoate) and Sulphur dioxide ( Potassium metabisulphite).
Food preservation is done to prevent spoilage of perishable food, increase the shelf life, availability of seasonal fruits through out the year at distant places and overcome the nutritional deficiency in the diet.

Washing of food material before consumption ensures removal of harmful pesticides and fumigants but repeated washing makes the food lose the nutritive value. Cooking at high temperature for a long time, use of baking soda, throwing away the soup of vegetable also causes loss of nutrients. Food items should be selected carefully, stored properly and cooked properly to maintain the nutritional value.