Teaching Environmental Studies Food and Nutrition Notes - Food and Nutrition

 

Food and Nutrition

 

Food are the substances which are essential for growth and development of an organism. All living organism need food, some of organisms such as plant make their own food by process of photosynthesis while animals obtain their food from plants and other animal. Human obtain food from both plants and animals.

 

Process of obtaining nutrients or food is called nutrition. Nutrients are the organic or inorganic substance which help in our survival and maintaining proper health. A nutrient supplies energy to the body, builds and repair body tissue and regulates the metabolism of body on the S of the quantity required by the body nutrients are classified into two categories.

 

1. Macro Nutrients These nutrients are required by body in large amount. e g. carbohydrate, fat and protein.

 

2. Micro Nutrients These nutrients are required only in minute or very small amount. e.g. minerals and vitamins. Micro nutrients basically help in regulation of different functions of body.

 

4.1 Food Products and their Sources

Food provides nutritional support to an organism, it usually of plant and animal origin and contains essential nutrients such as carbohydrates, fats, proteins, vitamins, or minerals. Some foods not from animals or plant sources include various edible fungi, especially mushroom. Fungi and ambient bacteria are used in the preparation of fermented and pickled foods like leavened bread, alcoholic drinks, cheese, pickles and yogurt.

 

Plant Foods  

 

Green plants are the primary source of food. There are around 2000 plant species which are for food and many of the species have several distinct cultivars.

 

Edible Parts of the Plant

Almost each and every part of the plant such as roots, stems, leaves, fruits and seeds are edible.                                                              

 

Roots Some roots store food are called as modified roots such as bulbs, corms rhizomes, and tubers. Example of modified roots are carrot, turnip, radish and beetroot etc. Carboydrate rich are mainly used in food, for animal feed and for manufacturing starch, alcohol and fermented beverages including beer.

 

Steins Main function of stem is to provide support to the plant but some stems get modified to store food, such as sugarcane, coriander etc. Potato is the example of stem tuber, ginger is a example of underground stem.

 

Leaves Green leaves are main source of calcium, we eat spinach, cabbage, curry leaves and many more in our food.

 

Seeds Edible seeds can be used as grains, pulses and oil seeds. Rice, wheat, jowar, maize, ragi etc are example of grains, grams, peas, beans are pulses and groundnut, sesame, mustard, coconut and sunflower seed are used as oil seeds.

 

Fruits These are the ripened ovaries of plants, including the seeds within. Many plants have evolved fruits that are attractive as a food source to animals, so that animals will eat the fruits and excrete the seeds some distance away. Fruits, therefore, make up a significant part of the diet.

Some botanical fruits, such as tomatoes, pumpkins and egg plants, are eaten as vegetables.

 

Vegetables These include root vegetables (such as potatoes and carrots), leaf vegetables (such as spinach and lettuce), stem vegetables (such as bamboo shoots and asparagus), and inflorescence vegetables (such as globe artichokes and broccoli).

Many herbs and spices are highly-flavourful vegetables.

 

4.2 Animal Product

 

Animals can be used as food either directly, or indirectly by the products they produce. Meat is an example of a direct product taken from animal, which comes from either muscle systems or from organs. Food products produced by animals include milk, eggs, poultry, meat, honey etc. Birds and other animals lay eggs, which are often eaten, and bees produce honey, a popular sweetener in many cultures.

 

4.21 Trophic Levels

 

·         The position which can an organism occupies in a food chain is called as its throphic level. A food chain represents a succession of organisms that eat another organism and are in turn eaten themselves.

·         All food chains and webs have at least two or three trophic levels. Generally, there are a maximum of four trophic levels.

 

Trophic Level	Where It Gets Food	Example
1st Trophic Level:   Producer	Makes its own food	Plants
2nd Trophic Level: Primary Consumer	Consumers producers	Mice eat plant seeds
3rd Trophic Level: Secondary Consumer	Consumes primary consumers	Snakes eat mice
4th Trophic Level: Tertiary Consumer	Consumes secondary consumers	Hawks eat snakes

 

Many consumers feed at more than one trophic level. Humans, e.g. are primary consumers when they eat plants such as vegetables. They are secondary consumers when they eat cows. They are tertiary consumers when they eat salmon, so it is called as omnivorous animal.

 

4.2.2 Foodchain

 

Every organism needs to obtain energy in order to live. e.g. plants get energy from the sun, some animals eat plants and some animals eat other animals.

 

·         A foodchain is the sequence of who eats whom in a biological community (an ecosystem) to obtain nutrition. A foodchain starts with the primary energy source, usually the in or boiling-hot deep sea vents.

·         The next link in the chain is an organism that make its own food from the primary energy source. An example is photosynthetic plants that make their own food from sunlight (using a process called photosynthesis). These are called autotrophs or primary producers.

 

·         In nature, basically two types of foodchains are recognised - grazing foodchain and detritus

foodchain.

 

1. Grazing Foodchain

·         This type of food chain starts from the living green plants goes to grazing herbivores, and on to carnivores. Ecosystems with such type of foodchain are directly dependent on an influx of solar radiation.

·         The phytoplanktons \[\to \] zooplanktons \[\to \] fish sequence or the grasses \[\to \] rabbit \[\to \] fox sequences are the examples, of grazing foodchain.

 

2. Detritus Foodchain

This type of foodchain goes from dead organic matter into microorganisms and then to organisms feeding on detritus (detrivores) and their predators.

Such ecosystems are thus less dependent on direct solar energy, e.g. such type of food chain operates in the decomposing accumulated litter in a temperate forest.

 

4.2.3 Food Web

 

A food web is several foodchains connected together. Another name for food web is a consumer-resource system. A foodchain only follows just one path as animals find food. A food web shows the many different paths plants and animals are connected, e.g. A hawk might also eat a mouse, a squirrel, a frog or some other animal. The snake may eat a beetle, a caterpillar, or some other animal. And so on for all the other animals in the foodchain.

 

4.3 Different Components of Food

 

There are different components of food namely carbohydrate, fats, protein, minerals, vitamins, roughage arid water.

 

4.3.1 Carbohydrates

 

They are chemically made up of carbon, hydrogen and oxygen. It provides energy to organism and it is primary source of energy to all living being on the Earth. These are the cheapest sources of energy.

There are three types of carbohydrate that animal consume in food. Namely starch, sugars and cellulose. There are three types of carbohydrate that animal consume in food, starch, sugars and cellulose.

 

Types of Carbohydrates

Carbohydrates are of three types

 

1. Monosaccharide Monosaccharides are simplest carbohydrates i.e. it cannot be hydrolyzed to smaller carbohydrates. General formula for monosaccharide is \[{{(C{{H}_{2}}O)}_{n}}\]

Some examples of monosaccharides are

Triose e.g. Glyceradehyde

Tetrose e.g. Erathrose

Hexose e.g. Glucose fluctose and galactose

 

2. Disaccharides These are made up of two monosaccharide molecules. General formula for disaccharides is \[({{C}_{12}}{{H}_{22}}{{O}_{11}})\] some examples of disaccharides are sucrose, maltose and lactose.

 

3. Polysaccharides These are made up of many monosaccharide molecules. General formula for polysaccharides is \[({{C}_{12}}{{H}_{22}}{{O}_{11}})\].

 

Common Sources of Carbohydrates

·         Some common sources of starch are cereals (wheat, rice and maize), millets (bajra, jowar, barley) and tubers (sweet p otato, topioca and potato).

Sugarcane, beet root, fruits, milk and honey are sources of sugars and cell walls of fruits, vegetables and cereals are source of cellulose.

 

·         During digestion both starch and sugars are absorbed as glucose. The surplus glucose is changed into glycogen which is stored in the liver for subsequent use.

·         Cellulose is a fibrous substance which is not digested by human body. However, it serves as roughage and facilitates bowel (stool) movement.

 

A normal person needs about 400-500 grams of carbohydrates daily in the diet. A growing child, a lactating mother and a person doing hard physical work need more carbohydrates than an average person because of their greater energy requirements.

 

Various Functions of Carbohydrates

Our bodies could not function without carbohydrates. It is a very important component of the food. Our brain especially relies solely on carbohydrates for its metabolic properties.

 

Functions of Carbohydrates

Essential functions that make carbohydrates important are as follow

 

1. Providing Energy Carbohydrates are the main energy source of the human diet. 1 gram of carbohydrate provide 4 kcal energy. Body gain direct energy from carbohydrates for metabolism and unused energy is stored in the form of glycogen in the body and whenever needed it will consume accordingly.

 

2. Prevent Ketosis by Sparing Protein When carbohydrate are absent in our meal then stored protein consumed by body as the energy source.

Proteins are necessary for synthesis of enzymes, antibodies etc so adequate intake of carbohydrate will prevent the degradation of skeletal muscle and other tissues such as kidney liver and heart hence ketosis prevented.

 

3. Dietary Fiber Cellulose, hemicellulose, pectingum and mucilage are dietary fibers. These dietary fibers are used as full for large intestine and are essential for proper intestinal health.

 

4. Flavour and Sweetness Carbohydrates provide sweetness to the food. Taste receptors of tongue bind with tiny bits of carbohydrates and send taste signals to the brain. Different carbohydrates have different level of sweetness e.g. fluctose is almost twice as sweet as sucrose and sucrose is almost sweeter than glucose.

 

5. Necessary for Fat Oxidation Our body need carbohydrates to burn fats. Carbohydrates break down into oxaloacetic acid. It is necessary to metabolise fats, without this break-down fats get converted into ketones, which is highly toxic to our body.

 

4.3.2 Fat

 

·         Fat is one of the three macronutrients along with carbohydrate and protein. We get heat and energy from fat. Fats are made up of carbon, hydrogen and oxygen like carbohydrates while oxygen is in lesser amount than carbohydrates.

·         The term oil, fat and lipid are often confused. Oil have short or unsaturated fatty acid chain and liquid at room temperature \[(20{}^\circ C)\]while fats are solid at room temperature lipids are not necessarily a triglyceride.

·         Fats are hydrophobic in nature i.e. soluble in organic solvents but insoluble in water. Fat are richest source of energy, one gram of fat after oxidation produce 9.0kcal of energy

 

Combination of Fat Fat is a organic substance which is composed by carbon, hydrogen and oxygen. Basic unit of fat is fatty acids.

Fatty acids are of following types

 

1. Saturated Fatty Acids This type of fatty acid have single bonds. Coconut oil and palm keinel oil are examples of saturated fatty acids.

 

2. Unsaturated Fatty Acids There is one or more double bond in the fatty acid chain in unsaturated fats. e.g. butter, ghee etc.

 

Functions of Fat

Fats provide various functions in our body. These are as follow

 

Provide Energy When carbohydrate is not available, fat is used as back up energy 1 gram of fat produce a calories (more than double the calories from protein and carbohydrates).

 

Vitamin Absorption Some vitamins are fat soluble these vitamines need fat for absorption. Vitamin A, Vitamin D, Vitamin E and Vitamin K are fat soluble vitamins.

 

·         Fat Storage for Subsequent Use If we consume more energy than the body needs to perform its normal functions, then excess food is stored as subcutaneous fat under the skin fat also stored around some vital organs, it helps in protection from any out side impacts or any sudden movements.

Maintain Body Temperature A thin fat layer located just underneath the skin, this layer help to insulate the body.

 

Protect Body Our Body has a layer of fat that surrounds major organs like nerves, tissues, brain heart, bones and act like a protective cushion.

 

4.3.3 Protein

 

·         Protein is a macromolecule, plays many critical functions in the body protein help in manufacturing and repairing of tissues. Proper development of bones, muscles, skin, nails and hair require protein, 1 gram of protein produce 4 kcal energy. Amino acids are the building blocks of proteins, these amino acids attached to one another in long chains.

·         These are 20 different types of amino acids that can be combined to make a protein.

Proteins are necessary for the formation of enzymes, hormones, haemoglobin and antibiotics. Our daily food should contain protein because it cannot be stored in the body for subsequent use.

 

Combination of Protein

 

·         Protein is a carbonic compound, which is formed by various amino acids. Main components of protein are carbon hydrogen, oxygen and nitrogen. Some phosphorus and sulphur are also present in smaller amount in protein. Carbon is present in 50%, hydrogen in 7%, oxygen in 23%, nitrogen in 16%, sulphur in 3% and phosphorus in 0.3%.

 

Sources of Protein

 

Protein is obtained from both animal and plant sources. Animals eat plant protein and make it according to their body. Human use both plant and animal protein, animal protein are move similar to our body so is better for consumption e.g. meat, fish, egg, milk and cheese etc. Some plant protein are also very important for our body. e.g. soyabean, dry fruits, groundnut etc.

Fruits and vegetables also have proteins.

 

Functions of Protein

Protein performs many Junctions and some of them are following

 

Repair and Maintenance

 

·         Protein is termed the building block of the body.

Protein is vital in the maintenance of body tissue, including development and repair. Hair, skin, eyes, muscles and organs all are made from protein.

·         This is why children need more protein per pound of body weight than adults; they are growing and developing new protein tissue.

·         Pregnant woman also need more protein intake in order to facilitate her child's development

 

Energy

 

·         Protein is a major source of energy. Protein is necessary for body tfssue maintenance and other vital functions. Our body will use this protein as energy source.

·         If it is not needed due to sufficient intake of other energy sources such as carbohydrates, the protein will be used to create fat and becomes part of fat cells.

 

Hormones

 

·         Protein is involve in the creation of some hormones. These substances help control body functions that involve the interaction of several organs. Insulin, a small protein, is an example of a hormone that regulates blood sugar.

·         It involves the interaction of organs such as the pancreas and the liver. Secretin, is another example of a protein hormone. This substance assists in the digestive process by stimulating the pancreas and the intestine to create necessary digestive juices.

 

Enzymes

 

·         The creation of DNA could not happen without the action of protein enzymes. Enzymes are proteins that increase the rate of chemical reactions in the body.

·         In fact, most of the necessary chemical reactions in the body would not efficiently proceed without enzymes, e.g. one type of enzyme functions as an aid in digesting large protein, carbohydrate and fat molecules into smaller molecules, while another assists the creation of DNA.

 

Transportation and Storage of Molecules

 

·         Protein is a major element in transportation of certain molecules, e.g. haemoglobin is a protein that transports oxygen throughout the body.

·         Protein is also sometimes used to store certain molecules. Ferritin is an example of a protein that combines with iron for storage in the liver.

 

Antibodies

 

·         Antibodies formed by protein which help prevent many illnesses diseases and infections. These proteins identify and assist in destroying antigens such as bacteria, viruses and other pathogens.

·         They often work in conjunction with the other immune system cells, e.g. these antibodies identify and then surround antigens in order to keep them contained until they can be destroyed by white blood cells.

 

4.3.4 Vitamins

 

·         They are chemical substance required by body in very small amount. They do not provide any energy to us but they are essential for proper metabolic functions of body, good health of body and protect body from various diseases e.g. vitamins help in keeping our eyes, bones, teeth and gums healthy.

·         Many chemical reactions in our body will not take place if vitamins not present. Vitamin A and D fat soluble.

·         While Vitamin C is a water-soluble vitamin and

Vitamin D is a fat-soluble vitamin. It is found in fish oil, eggs, milk and milk products. Sunlight is the main source to form .vitamin D by skin.

·         Vitamin D helps our body to use calcium for bones and teeth Ricket is the disease cause by the deficiency of Vitamin D.

 

Vitamins: Their Functions and Sources

 

 

Vitamins	Daily Requirement for 13-15 Year Child	Functions	Best Food Sources
Vitamin A (Retinol) Vitamin B1 (Thiamine)	750 mg 1.3 mg (boys) 1.2 mg (girls)	Maintenance of vision and skin; essential for synthesis of visual pigment. Carbohydrate metabolism; sharpens appetite; functioning of heart, nerve and muscles.	Milk, cheese, butter, eggs, olive oil, carrots, mangoes, papaya, yellow pumpkin, spinach, sweet potato. Yeast; liver; milk; cheese; leafy vegetables; meat; whole grain cereals.
Vitamin B2 (Riboflavin)	1.6 mg (boys) 1.4 mg (girls)	Carbohydrate and protein metabolism; keeps skin healthy.	Milk; liver meat; eggs peas; yeast; whole grains; green leafy vegetables.
Vitamin B3 (Niacin)	1.8 mg (boys) 1.5 mg (girls)	Protein, fat and carbohydrate metabolism. Keeps the skin healthy.	Fish; eggs; meat; legumes; whole grains; leafy vegetables; peanuts; bean; tomato; potato.
Vitamin B12 (Cyanocobalamine)	0.2-100 mg	Blood formation Nervous tissue metabolism, Nucleic acid synthesis.	Liver; fish; cheese; milk, eggs; meat.
Vitamin C (Ascorbic Acid)	40 mg	Resistance to infections; keeping teeth, gums and joints healthy; healing of cuts and wounds, maintenance of connective tissue.	Amia, cabbage; tomatoes, lemon; orange; mangoes; chillies, guava, pineapple; sprouted grams.
Vitamin D	20 mg	Keep teeth and bones healthy, absorption of calcium and phosphorous.	Milk, cheese; egg yolk; fish, fish butter; exposure to sunlight.
Vitamin E (Tocopherol)	Trace amount	Antioxidant ageing vitamin.	Grains vegetable oil, green leafy vegetables, nuts.
Vitamin K (Phylloquinone)	Trace amount	Clotting of blood.	Green leafy vegetables, soyabean tomatoes.

 

4.3.5 Minerals

 

·         12Minerals are required in very small amount by our body so are called as micronutrients. Calcium phosphorus, sodium, potassium, chlorine, sulphur, iron, iodine and copper are present in our body.

·         Each one of these minerals is necessary for a proper growth of the body and to maintain good health.

·         Calcium and phosphorus are important for good health of bones and teeth. Calcium is found in milk, skimmed milk and buttermilk, cheese and green leafy vegetables. Ragi is also good source of calcium.

 

Minerals and their Sources

Phosphorus found in milk cereals, pulses, fish and meat. Children need relatively more calcium and phosphorus for the growth of their bones. Pregnant and nursing mother also need more calcium and phosphorus.

Iron is essential for the formation of haemoglobin in blood. Leafy and green vegetables, nuts and other green vegetables, nuts and jaggery are rich in iron Anaemia can be caused by the deficiency of iron.

Iodine is also essential for proper functioning of the thyroid glands. It is require in very small amount.

Deficiency of iodine can cause goiter, due to which glands of neck appear swollen. Children can be mentally retarded due to deficiency of iodine.

 

4.3.6 Roughage

 

·         It is the fibre present in some food items like fruits and vegetables. Roughage consists mainly of cellulose. Though roughage does not provide nutrients to our body, but it is essential as it helps in the regular movement of the bowel.

 

Some functions of roughage are

·         It helps in bowel movement.

·         It cleans our digestive tracts and protects from digestive ailments. It prevents constipation.

·         It helps in retaining water in the body.

·         It helps in maintaining optimum levels of blood sugar and cholesterol.

 

4.3.7. Water

 

It is an important constituent of our diet. 75% of an infant body and 70% of an adult body is made up of water. Our body need about 2-3 litres of water daily,

 

 

Functions of Water

 

Following are the functions of water in our body

·         Water is essential for all the reactions in the cells in which energy is produced or utilised.

·         Water is the main constituent of blood and blood plays an important role in transporting substances to different parts of the body.

·         Water make our body hydrated, a person becomes dehydrated if body lost too much of water by various means like loose motion, vomiting, too much sweating etc. The blood gets thicker during dehydrated conditions, it starts moving slowly around the body hence cause severe pain and cramps in muscles.

·         Water helps in digestion.

·         Water dissolves waste products of the body so that these could be removed through urine.

·         Water help to maintain body temperature through sweating and evaporation from skin.

 

4.4 Balance Diet

 

·         Food provides us energy and nourishment for proper growth and maintenance of our body, we can have healthy body by taking a balanced diet. A balanced diet contains various groups of foodstuffs.

Such as energy giving foods, body- building foods and protective foods in correct proportions.

·         According to age, sex and physical activity of an individual the components of the balanced diet differs.

·         Beside balanced diet one should, do sufficient exercise have flesh air, water and sunshine.

Adequate physical and mental rest is the other essential requirement of the body.

 

4.4.1 Nutritional Needs Human

 

Human needs different nutritions in various stages of development and on the basis of their physical conditions and on the basis of occupation.

These are as follow

 

Nutritional Needs for Growing Children

Growing children need more food in proportion to their body weight.

They need

·         extra protein to make new tissues for growth.

·         more calcium and phosphorus for formation of bones and muscle cells.

·         Vitamin A for development of healthy eyesight.

·         Vitamin C for general health.

·         Vitamin D for healthy bones.

 

Nutritional Needs for Persons in Different Occupation

·         Persons doing hard physical work like rickshaw pullers, labourers, carpenters, millworkers etc require food which is rich in energy (carbohydrates and fats).

·         Similarly, athletes also require diet of high energy value.

Nutritional Needs During Pregnancy and Lactation

·         A pregnant woman has to feed the developing embryo, therefore, has special need for extra nutrients. Pregnant woman and lactating mothers should take extra protein for tissue growth.

·         more calcium and phosphorus to form bones of the baby.

·         more iron for making sufficient blood of the baby.

·         more carbohydrates for herself because extra energy is required to carryout all the building processes linked with embryo.

·         Similarly, nursing mothers (who breast feed their babies), also need a special diet to take care of their additional requirements of lactation (milk formation).

·         So, their diet should contain more proteins, calcium and vitamins.

Nutritional Needs Depending Upon the State of Health

The person recovering from illness need more proteins, minerals and vitamins in their diet to repair the damage caused by the ailment. If there is loss of blood due to surgery or an accident the patient needs more of proteins and iron to make up for the loss of blood.

 

4.5 How do We Make and Eat Food?

 

·         We eat both cooked and uncooked food. Some foods can be eat uncooked like most of the fruits, salads etc while some of the foods are those that we need to cook it first then only we can eat them e.g. cereals, pulses, most of vegetables.

·         Cooked foods are easy to digest and they are germ free because during cooking germs are killed but food should not be over cooked as it will destroy the nutrient of food.

There are three main methods of cooking

 

4.5.1 Moist Heat Method

 

These are the methods in which we use the heat generated by water in some form or the other. The methods include boiling, steaming, pressure- cooking, and stewing.

 

Boiling

 

·         In this method, the foodstuffs are cooked in boiling water. Thus, the food comes in direct contact with water. Foodstuff are immersed in water in suitable container and heat is applied untill the food become tender. Foods that are cooked by boiling are rice, eggs, dais, potatoes, meat, and sago and beetroot. Boiling can be done with excess of water (eggs) or with sufficient water (dal, upma).

·         Food cooked by this method is always recommended for patients. Excessive boiling can drain the minerals and vitamins from the food and can harm the colour of the vegetables.

Steaming

·         Steaming is also a method of cooking food with water, but in this case, the food does not come in direct contact with water. In this method, the food is cooked by the heat generated by steam and hence takes a slightly longer time, as compared to boiling.

 

Pressure Cooking

 

In this method, the food is cooked under pressure and with increase in pressure the temperature also correspondingly increases. Thus, the food is cooked very fast. Actually, it is a type of steaming only, in which water is boiled under high pressure, thus raising temperature and reducing the cooking time.

 

Stewing

 

·         This is a very gentle method of cooking, in which the food is cooked in a closed pan using only a small quantity of liquid. Once the liquid reaches the boiling point, the heat is reduced, which makes it a slow and long process.

·         The amount of water left after cooking is only marginal i.e. 1 to 2 tablespoons which is served along with the food. Thus, the flavour of food is fully retained. The foods which are generally stewed are fruits, vegetables, meat etc.

 

Simmering

 

·         When foods are cooked in a pan with a well-fitting lid at temperature just below the boiling point 82-99 degree congregates of the liquid in which they are immerse, the process is known as simmering.

·         It is a useful method when foods have to be cooked for a long time to make it tender as in the case of cheaper cuts of meat, fish cooking, custards, kheer, vegetables and carrot halwa.

This method is also employed in making soups.

 

4.5.2 Fry (Cooking by Fats)

 

·         This is a method of cooking in which the food is cooked by the heat of hot fat. Fat or oil can be heated to a much higher temperature, as compared to water and thus, as the food comes in contact with this heated fat, it gets cooked quickly. Fried food are very tasty and hence popular in our meals.

·         There are three types of frying: (1) Sauteing (2)

Shallow fat frying (3) Deep fat frying.

These are explained below

 

Sauteing

 

·         This means to toss the foodstuff in a little amount of heated fat, till it is partially cooked and absorbs the fat. The food is tossed occasionally or turned over with a spatula to enable all the pieces to come in contact with the oil and get cooked evenly.

·         Sometimes the pan is covered till tender in its own steam. The product obtained in cooked by this method is slightly moist, tender but without any liquid or gravy.

·         It is usually done as a pre-preparation step in many dishes e.g. sauteing of vegetable in the preparation of vegetable pulao or sauteing of noodles, thin pieces of meat etc.

 

Shallow Fat Frying

 

·         In this method, a shallow pan like frying pan or an ordinary .griddle is used in which the food is fried in little amount of fat. During frying, it is turned over, so that it may be evenly browned on both the sides.

In this case also, the fat used is usually absorbed by the foodstuff.

·         The preparation generally cooked by this method are parantha, omellete, tikkes, pancakes etc. Some food contain sufficient fat in themselves like bacon and sausages. Hence, these can be fried with the addition of any fat.

 

Deep Fat Frying

 

·         The food is completely immersed in hot fat and therefore a deeper utensil like karahi and a large quantity of fat is required. The fat is heated in the

karahi and as it becomes hot, the food to be fried is put in it which gets cooked quickly. Common preparations which are made by this method are poories, pakoras, cutlets, samosas etc.

·         While deep frying care should be take to see that the fat does not get overheated, as the fat decomposes at high temperature, which not only spoils the taste of the food, but is even harmful for our body.

 

4.5.3 Dry Heat Method

 

In this method, water and oil are not used only heat is used to cook the food. Following are the method of dry heat cooking method

 

Baking

 

·         It is cooking of food in hot air in oven. The food to be cooked is kept in a preheated oven, where it is surrounded by hot air in the closen oven, thus getting cook by the dry heat. Usually, the oven is heated to a particularly temperature according to the food which is to be baked and this temperature is maintained throughout the cooking procedure.

The foods generally prepared by this method are: cakes, biscuits, pies, pastries, pudding, vegetables, and potatoes etc.

 

Roasting

 

It is cooking the food uncovered in hot air i.e. by dry heat. This can be done in a tandoor, in an even or in a thick heavy pan.

Certain foods like chicken, joints of good quality meats, are roasted with occasional basting i.e. addition of a little fat, so as to prevent the surface from drying add to ah flavour, whereas vegetable likes potatoes sweet potatoes and bringers are 1 roasted on a direct flame or in a oven without addition of any fat.

 

Food Habits of Different Regions

 

Region/Place	Food Matenal
Hong Kong	Ling-hu-fen (meat of snake)
Kashmir	Fish cooked in mustard oil
Goa	Fish (cooked in coconut oil)
Kerala	Tapioca and curry made of coconut, fish cooked in coconut oil
Coastal area in South India	Sea food cooked in coconut oil
Ahmedabad or Gujarat	Dhokla with chutney, lemon rice and mithai
Valsad	Batata vada, puri-shook, doodh
Udupi	Idli-vada
Bihar	Litti chokha
Mizoram	Rice
Assam	Rice, tea and pitha, bhat-sukho, luchi and chola-dal

 

4.6 Food Maintenance

During various stages of production and consumption, food can get contaminated.

Maintenance of food involve all the stage viz. production handling storage, distribution, cooking and serving of all type of food should.

 

4.6.1 Food Preservation

·         Food storage is most important step in maintenance of food. Food can be divided in two types according to storage one is perishable food cannot be stored for long time like milk, vegetables fruits boiled rice and most of the cooked food and other one is nonperishable food can be stored for long periods without getting spoiled, e.g. wheat rice, pulses etc.

·         According to perishable food and non-perishable foods, storage are of two types viz. cold storage and dry storage, perishable food are stored in cold storage under very low temperature, spoilage of perishable foods is due to the action of micro organisms, present in them or in the surroundings.

·         Low temperature of cold storage slows down their growth and thus prevents the spoilage of foods materials, storage of perishable food materials at low temperature helps retain their nutritive value and reduce losses from spoilage.

·         Non-perishable food e.g. food grains, flour cereals, sugar and spices are stored under dry storage. Dry storage done at room, temperature, place for dry storage should be- clean and dry cool, well ventilated, free from rodents and insects.

Some food preserved in-following ways

·         Pasteurisation is the process of heat proc a liquid mainly milk juice canned food etc to kill pathogemi invented by Louis pasteur.

·         Milk is pasteurised at \[161{}^\circ F\] \[{{B}_{3}}\] for 15 sec or

\[145{}^\circ C\text{ (}63{}^\circ C\text{)}\]for 30 minutes.

·         Food poisoning mainly caused by microorganisms like bacteria which can reproduce rapidly. The common example of such bacteria are salmonella and clostridium.

·         The prevent food poisoning careful treatment of food should be done while it is being produced processed stored and cooked.

 

4.6.2 Recycle and Decomposition

 

·         Food materials can be easily subjected to decomposition as food material are of biological origin they will degrade in the environment naturally. Things like left over food, peels of vegetable and fruits can be subjected to decomposition and they can be later used as manure.

·         While many accessory articles which helps in storing food article, cooking food articles other utensils made up of steel, other metals and plastics can be recycled only. However, earthen ware can be destroyed easily and it will mix with the soil.