Health and Hygiene Tnpsc
The basic necessity of life. Food is defined as any substance from a plant or animal that provides nutrition like protein, fats, vitamins, minerals, and carbohydrates for growth, energy, repair of body parts such as bones and tissue and provides protection from diseases.
Classification of nutrients by predominant function
The nutrient is classified into Proteins, Minerals, Carbohydrates, Fats, Vitamins, and Water
These are organic compounds made of carbon, hydrogen, and oxygen in the ratio 1:2:1. It is the main source of energy.
Edible sugar, cellulose, starch, rice, etc are some sources. Glucose is a monosaccharide, sugar is a disaccharide, and cellulose in the vegetable is a polysaccharide.
Honey, sugarcane, and fruits are sources of sucrose. Starch is from rice, potatoes, and bread.
Glycogen is stored in the muscles and liver of living organisms. A plant cell is made of cellulose and other complex organic compounds.
Deficiency of Carbohydrates
The body suffers from glucose, then it takes energy from proteins and fats. Dizziness, physical and mental weakness is caused due to suffering of the central nervous system from insufficient glucose. It causes low blood sugar called Hypoglycemia.
It is an essential nutrient, the building block of body tissue, and also a fuel source.
Protein provides more energy than carbohydrate that is carbohydrates provides 4 kcal(17 kJ) per gram and lipids provides 9 kcal(37 kJ) per gram.
The most important point of protein is its amino acid composition. Proteins are made of polypeptide chains which are composed of amino acids that are linked by peptide bonds.
Proteins are broken down into smaller polypeptides during digestion in the stomach and small intestine by the action of proteases.
Proteases are important for the absorption of essential amino acids that cannot be synthesized by the body.
There are 9 essential amino acids(EAA) that are crucial for human needs and to prevent malnutrition. They are phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine.
Known as triglycerides that are esters of free fatty acid chains and glycerol. Fat is crucial for structural and metabolic functions.
An essential part of the diet for most heterotrophs. During digestion, Lipase enzymes break down fats in the small intestine.
These essential fatty acids cannot be produced in the body therefore it is taken into the diet. There are two essential fatty acids (EFAs) that are alpha-linolenic acid (omega-3 fatty acid) and linoleic acid(omega-6 fatty acid).
Deficiency of Fats
Eating disorders, Causes Vitamin deficiencies such as Infertility, Night Blindness, etc as fat helps in absorbing vitamins, inflammatory bowel disease, cystic fibrosis, pancreatic insufficiency, etc.
Essential nutrients are taken a very minute amount to maintain special functions such as body health etc.
Vitamins are not produced by the body, so they must be taken in a small amount through diet.
A chemical element that is very vital to perform certain functions in the body.
Minerals are inorganic substances produced by the earth which important to the physiological process and they are important constituents of teeth, bones, tissues, blood, muscles, and nerve cells.
5 major minerals in humans are calcium, phosphorus, potassium, sodium, and magnesium. The remaining minerals are called Trace elements that are Iron, cobalt, copper, zinc, manganese, chlorine, sulfur, molybdenum, iodine, and selenium.
Facts on essential nutrients and their functions
Dr. Funk coined the term Vitamin. Vitamin A was first as A is the first letter of the alphabet.
Vitamin D, helps bones absorb calcium. Iron from meat (heme iron) is readily absorbed.
Irom from the plant (non-heme iron) required Vit-C to get absorbed. Vit-D is produced when the skin is exposed to sunlight, as skin dehydro cholesterol is converted into Vit-D. Vit-D is also called as Sunshine vitamin.
The world iodine deficiency day is celebrated on October 21.
Vital as a solvent, the body’s solutes dissolve in water and are also important for metabolic processes. There are two types of metabolism with respect to water that are anabolism and catabolism.
Anabolism-Water is removed from molecules by enzymatic chemical reactions to synthesize larger molecules such as starch, triglycerides, and proteins.
In catabolism, water is used for breaking bonds to produce smaller molecules such as glucose, fatty acids, and amino acids which are used for fuel and other purposes.
Without water, body metabolism will not exist.
Types of nutritional disorders and symptoms
Fat-Soluble Vitamins- Vitamin A, D, E, K
Sources of Vitamin A-Carrot, papaya, leafy vegetable, fish liver oil, egg yolk, liver, dairy products.
Disorder- Xerophthalmia, Nyctalopia (Night Blindness)
Symptoms-Dryness of Cornea( Xerophthalmia ), Nyctalopia -unable to see at night and dim light, scally skin.
Egg, liver, dairy, fish, sunlight
Disorder- Rickets in Children
Symptoms- Bow Legs, defective ribs, development of pigeon chest.
Whole wheat, meat, vegetable oil, milk
Disorder- Sterility in rats, Reproductive abnormalities.
4.Vitamin-K(Derivative of Quinone)
Leafy vegetables, soybeans, milk
Disorder- Blood clotting is prevented.
Symptoms- Excessive bleeding due to delayed blood clotting.
Water-Soluble Vitamins- Vitamin B1,B2,B3,B6,B12,C
Whole grains, yeast, eggs, liver, sprouted pulses.
Symptoms- degenerative nerve & muscle weakness, paralysis
Milk, egg, liver, green, vegetables, whole grains
Symptoms- Eye Irritation, Dry Skin, inflammation of lips, fissures in the corner of the mouth.
Milk, eggs, liver, lean meat, groundnuts, bran
Symptoms- Inflammation of skin, loss of memory, diarrhea
Milk, eggs, germs of grains and cereals, rice, polishings
Symptoms-Scaly skin, nerve disorders
Milk, meat, liver, pulses, cereals, fish
Disorder- Pernicious anemia
Symptoms- Decrease in red blood cell production, degeneration of the spinal cord
6.Vitamin C(Ascorbic Acid)
Leafy vegetables, sprouts, citrus fruits like gooseberry(Amala), lemon, orange
Symptoms- Swollen and bleeding gums, delay in wounds healing, teeth and bones malformed.
Protein Energy Malnutrition(PEM)
Severe protein deficiency affects children age 1-5 whose dietary intake is mainly carbohydrate but poor protein intake.
Affects infants below the age of one, who have a poor intake of carbohydrates, fats, and proteins.
Functions of minerals in the body
Sources-Dairy, beans, cabbage, eggs, fish
The function of Calcium-Constitution of bone, the enamel of teeth, clotting of blood and controls muscle contraction
Disorder-Bone deformities, poor skeletal growth, osteoporosis in adults.
Sources- Table Salt.
The function of Sodium- maintains fluid balance and is involved in neurotransmission.
Muscular cramps, nerve impulses do not transmit.
Sources- Banana, sweet, potato, nuts, whole grains, citrus fruits.
The function of Potassium- Regulates nerve and muscle activity
Disorder-Muscular fatigue, nerve impulses do not transmit.
Sources- Spinach, dates, greens, broccoli, whole cereals, nuts, fish, liver
The function of Iron- An important component of hemoglobin
Sources- Milk, Seafood, Table Salt.
Functions of Iodine- Formation of Thyroid hormones
Disease caused by excessive intake of Vitamins is called Vitaminosis.
Hyper Vitaminosis is a condition of abnormally high storage of vitamins which can lead to toxic symptoms
Example: Excess vitamin-A intake can lead to Vitaminosis A.
A right balanced diet is required for preventing Vitaminosis.
Healthy food pyramid
The food on top of the pyramid should be consumed in less quantity such as fat and oil.
The food at the bottom of the pyramid should be consumed more compared to the top of the pyramid.
undesirable change of fresh food at normal state to a condition which is not suitable for human consumption.
Signs of food spoilage are changed in color, bad odor, texture, and taste change.
Two reasons for spoilage are Internal and External factors.
External factors- adulterants, contaminated utensils, lack of storage, poor hygiene.
Internal factor- Enzymatic activities and moisture content of the food.
Control and Prevention of Food spoilage
Food Preservation- Process to prevent food from decay or spoilage.
Food is preserved to increase the shelf life of food, to retain the color/texture /flavor / and nutrition value, to increase food supply, decrease food waste, add variety to the food.
Methods of Food Preservation
The process of removing water content from the food. It is done by Sun Drying(Fish, Cereals) or vacuum drying (e.g milk powder, cheese powder), or hot air drying (e.g grapes, dry fruits, potato flakes). Dried neem leaves, turmeric are used to prevent grains from insects and beetles.
Meat and fish are exposed to smoke, the food is dried using smoke that preserves the food.
The food is exposed to controlled ionizing radiation like x-ray, gamma rays, or UV rays to kill microbes to prevent the food from spoilage. This process is also called cold pasteurization as the product is not heated. Done on onions and potatoes to increase its shelf life.
Use of Inert Gas
Nitrogen gas is filled in air-tight packets containing food which inhibits the growth of fungus. Ex: Used in Potato wafers.
Storing in a refrigerator inhibits the biological and chemical reaction thus preventing food from spoilage.
Storing food below zero degrees Celcius at which microorganisms cannot grow and the metabolic reaction is reduced. Deep Freezing – -23 to -30 degrees Celcius.
Named after Louis Pasteur that involves boiling milk to 63-degree Celcius for about 30 minutes and suddenly cooling to kill the microbes present. Louis Pasteur also developed vaccines for rabies and anthrax.
Food products are stored in clean, steamed airtight containers under pressure and then sealed and subjected to high temperature and cooled to destroy microorganisms.
There are two types of preservatives Natural and Synthetic.
Salt removes water from food by the process of osmosis. Example Meat, Fish, Raw mangoes are preserved using this process also referred to as pickles.
Sugar/Honey is also used to increase the shelf life of fruits. The process is similar to salt. Ex Jam, Jellies, squash. The hygroscopic nature of sugar/honey, reduces the water in food, and prevents it from oxidation, and prevents spoilage from microbes.
The oil prevents food from external contact such as air, prevents micro growth over the food.
Excess content oil, salt, and sugar make food unsafe for consumption, especially for Diabetes, obesity, and heart diseases.
Sodium benzoate, citric acid, vinegar, sodium meta bisulfate, and potassium bisulfate are added to jam, jellies, sauces, and other packed and ready-to-eat items.
October 16th is world food day
Adulterants and Diseases
The addition or removal of any substances to the food, as the natural composition and quality of food, get affected.
Today every food is adulterated such as Milk, cereals, meat, etc.
Classification of Adulterants
Adulterants are classified into Natural, Unintentional, and Intentional.
Present or grow naturally in food, chemical, or organic substance or microbes such as fungus.
Example: Toxin substances in poisonous mushrooms, prussic acid in apple seeds, cherry and peach pits, marine toxin, fish, oil poisoning, pollution in the air, water, and land.
Incidental food adulteration or Unintentional adulteration
Added without knowing it is harmful. Generally done while packing or transporting.
An example is Pesticide residues( adding pesticides to crop and ignorance of clearing it), Rodent( larva, mice, and insects bits, this food and spread the disease during storage, Microbial containing such E.Coli(Escherichia coli), Salmonella in fruits, meats.
Intentionally added adulterants
Intentionally added to food for financial gain.
Some of Intentionally added Adulterants
Additives and preservatives such as vinegar, citric acid, sodium bicarbonate(baking soda), hydrogen peroxide in milk, modified food starch, food flavor, the artificial sweetener.
Artificial ripening of fruits using Calcium Carbide.
Artificial coloring agents use a chemical such as Metallic lead for green leafy vegetables, bitter gourd, green peas.
Edible synthetic wax-like shellac or carnauba wax coated on apple, pear to give a shiny appearance.
Growth hormones for Cattle, Poultry, and also for the plant.
Diseases caused by adulteration of food are Fever, Kidney Disorder, Nausea and Diarrhoea etc
Some simple techniques used to detect adulterants at home
Milk flows slowly and leaves a trail behind when a drop of milk is on a slanting polished surface. While adulterated milk with water flow fast and leaves no trail behind.
Pure honey burns while adulterated honey produces a cracking sound.
Sugar Dissolve completely in water, while sugar adulterated with chalk powder settles down.
The coffee powder floats in water, while coffee powder adulterated with tamarind powder settles down.
Sand grit, marble, stones present in food grain can be removed by handpicking, sorting, and washing.
Quality Standard Control Agencies
ISI, Agmark, Fpo, FCI.
FCI(Food Corporation of India)
Set up in the year 1965 for safeguarding the interest of farmers, distribution of food, maintaining food stock for national food security, and regulating the market price of food grains.
ISI (Indian Standards Institution)
Now known as Bureau of India Standard (BIS). It certified electrical and electronic appliances.
AGMARK (Agricultural Marking)
Agmark certifies agricultural and livestock products such as pulses, honey, butter, etc.
FPO (Fruit Process Order)
Certified vegetable and fruit products such as Jam, Sauce, Pickles, etc.
Food Safety and Standards Authority of India
FSSAI regulates and supervises food safety and quality for promoting public health.
Codex Alimentarius -Global standard for foods approved by World Trade Organisation(WTO).