Food Production & Management

Science II – Class IX

What / Why / How ? - In food management

• WHAT are the constituents / components present in the food we eat daily?

• WHAT are the nutritional significances of various foods ?

• WHAT type of disorders arise out of deficiencies ?

• HOW do I follow a balance in diet ?

• WHY does the food gets spoiled ?

• HOW to preserve food and WHAT are the methods adopted ?

Food production & Management - UnpluggedConstituents of food & Deficiency disorders & Nutritional significance Balance diet

Food spoilage – Causes, Methods of storage -precautions & prevention Food Prevention

Food – what is it made of ?

• FOOD – Food is defined as a substance which is a source of energy and provides materials for the growth and development of body.

• It is necessary for all metabolic processes and to maintain constant body temperature.

• We need to know the composition of the food we take daily and how it provides energy required by the body for all the metabolic activities .

Energy…… what is it all about ?

Astronauts require more energy in weightless conditions of the space. They need 12500 KJ of food energy daily. Yet they lose weight on space flights lasting more than 2 weeks. Hence they are provided with high energy special foods.

BMR (Basic Metabolic Rate):The minimum energy required by the body when its at rest, to carry on the metabolic functions is called Basic Metabolic Rate

When energy is required Adenosine disphosphate is converted into Adenosine triphosphate and energy is released.Excercises like brisk walking, swimming, running and yoga help in reducing over weight.

Constituents of Food

• Constituents of food can be divided into 3 groups based on their functions as follows

Energy releasers Body builders Regulators

Constituents of Food

Energy releasers

Carbohydrates

Lipids

Body builders

Proteins Minerals Water

Regulators

Vitamins Minerals

Constituents of Food…..... contd

Energy releasers:• Carbohydrates and Lipids are the major energy releasing nutrients.• They release energy required for the body when they undergo oxidation. Hence they are called

energy releasers.

Body builders:• Proteins, minerals and water are the chief constituents required for the formation of tissues which

in turn build the body.

Regulators:• Vitamins and minerals are required in small quantities for the body. They regulate and co-ordinate

various activities of the body and are hence called as Regulators.

If these nutrients are not supplied sufficiently for a long time, it results in deficiency disorders. This condition is generally known as Malnutrition.

In next slide, we will learn more about energy requirements and various associated terms.

Constituents of Food…..... contd

Carbohydrates

• Carbohydrates are naturally occuring macronutrients. • They form a major component of living organisms. It includes sugar, starch and cellulose.• They provide around 70% – 80% of the energy required by the body for an average adult. They are

produced by green plants during photosynthesis.• Energy is also required for growth, functioning of the muscles, during exercise/physical activity and

to maintain body temperature.

Nutritional significance of CARBOHYDRATES Nutritional disorders due to CARBOHYDRATES deficiency

Sucrose, fructose, Galactose, maltose and starch are the primary carbohydrates present in our food and they are converted into glucose during digestion.

Deficiency of carbohydrates causes • Weakness• Retardation of growth in children

Glucose is oxidized in the mitochondria to release energy during cellular respiration.

Excess intake of carbohydrates causes• Obesity mainly in middle aged people.• Hypertension, diabetes and heart diseases are in turn caused by

Obesity.

The energy thus released by the cells is used for various metabolic activities.

Body weight can be brought down by reducing the intake of carbohydrates in the food.

The excess energy is stored as ATP molecules. Taking up physical activities like excercise also helps to reduce weight.

Constituents of Food…..... contd

Lipids

• Lipids are macromolecules which are generally stored in the body. Lipids include fats, oils, waxes

and steroids.

• Fats and oils are called dietary lipids. They are stored in the body and serve as fat reserves.

• Fats like butter & ghee are solid at room temperature. They are made up of Saturated Fatty Acids.

• Liquid oils like groundnut oil and sunflower oil are made up of Unsaturated Fatty Acids.

• The human body can synthesise many fatty acids and they need not be essentially included in the

diet. These are called Non-essential Fatty Acids. Eg) Glycine

• Fatty acids that are not synthesised in the body need to be included in the diet. These are called

Essential Fatty Acids. Eg) Linoleric acid and Linolenic acid.

Constituents of Food…..... contd

Nutritional significance of LIPIDS Nutritional disorders due to LIPID deficiency

Fats and oils are digested into glycerol and fatty acids. Fatty acids are oxidized during cellular respiration. But they release much more energy.

Cholesterol is a type of fat. It is needed for producing steroids and vitamin D.

Fats stored in the adipose tissues are concerntrated source of energy. They release energy during fasting.

Excess of cholesterol in body gets deposited in arteries and causes• Artherosclerosis.• Heart diseases

Lipids are necessary for absorbing fat soluble vitamins like A,D,E,K and carotenoid.

Deficiency of Lipids causes• PhrynodermaSymptoms are skin eruptions on limbs, back and buttocks. The skin becomes dry and thick in children.

Steroids and related compounds are substances which regulate the growth and development of the body.

Proteins

• Proteins are one of the macronutrients required by the body. They are found abundantly in all living tissues.

• Proteins are made up of Amino acids. Like Fatty acids, Amino acids can also be classified as ESSENTIAL and NON-ESSENTIAL

• Proteins which are rich in ESSENTIAL amino acids are called High Quality Proteins.eg) Proteins found in milk, milk products, meat, fish and eggs are high quality prooteins.

• Soya beans, pulses, ground nuts and oil seeds are sources of proteins for vegetarians.

Constituents of Food…..... contd

Proteins…contd

Nutritional significance of PROTEINS Nutritional disorders due to PROTEIN deficiencyProteins are needed for continuous building of tissues in body. 2 most common protein deficiency disorders seen in developing countries

are• Kwashiorkar• Nutitional marasmus

They are essential for maintenance of tissue, replacement of lost/damaged tissues in the body.Children affected with KWASHIORKAR

Kwashiorkar:• It was first found in West Africa. It affects children < 5 years of age who do

not get enough protein supplement, even though they have enough carbohydrates which supplies adequate energy.

• Symptoms of Kwashiorkar are i. Retarded growthii. Swelling of abdomen, legs and feetiii. Decolourization of skin and hairiv. Muscle wasting and mental retardation

• These effects are irreversible and if the above symptoms become severe, it may lead to death.

• But the child’s health can be recovered if protein rich foods such as soyabean, groundnut, banana and boiled vegetables are given.

All the enzymes which regulate metabolic reactions in our bodies are proteins.

Child sufferingfromNUTRITIONALMARASMUS

Nutritional marasmus:• If both proteins and calories are deficient in a diet, it leads to a condition

called nutritional marasmus.• It generally occurs in children < 1 year of age if they are not fed by

mother’s milk.• The symptoms are similar to Kwashiorkar. The child also develops loose

skin all over the body due to muscle wasting.• This condition can be brought back to normal if easily digestible and

absorbable form of proteins is given in early stages of the disorder.

Proteins in the form of antibodies help in resisting infections and provide immunity.

Soya bean, groundnut, banana, milk & cooked cereals are some foods which provide a good substitute for mother’s milk and supply proteins and calories.

Constituents of Food…..... contdVitamins• Vitamins are a diverse group of organic compounds which are vital for normal growth,

development and maintenance of body.• They are required in very small quantities.• Many of the vitamins cannot be synthesized by our bodies. They have to be included in out diet.• Vitamins can be classified as 2 types

i) Fat soluble ( eg: Vitamin A, D and K )ii) Water soluble (eg: Vitamin B complex & C )

Following table shows some of the sources, functions and deficiency disorders of various types of vitamins.

Name of VITAMIN Sources Functions Deficiency diseases

Vitamin ‘A’ Green leafy vegetables, carror, milk, milk products, fish & fish liver oil.

Increase resistance power against diseases, protects the eyes from infections, helps in seeing in dim light, required for making rhodopsin.

Retarded growth, health of the skin is affected, night blindness leading to Xerophthalmia.

Vitamin ‘D’ Fish liver oil, milk, butter, eggs, It is manufactured in the body by sunlight and hence called as SUNSHINE vitamin.

Helps the body absorb calcium from food.

Brittle bone, Osteomalacia in adults, rickets in children. Symptoms – poor growth, deformation of bones resulting in bow legs & defective ribs, teeth, skull. Symptoms of rickets – enlarged ribs.

Constituents of Food…..... contdVitamins

Name of VITAMIN Sources Functions Deficiency diseases

Vitamin ‘E’ Milk, egg yolk, wheat, maize, green vegetables, oils & animal food products.

Anti oxidant, protects vitamins A, C, D, K and unsaturated fatty acids.

Poorly understood in humans. Causes sterility in rats.

Vitamin ‘K’ Green vegetables, legumes, milk , milk products, pig’s liver, egg yolk, produced by bacteria in gut.

Helps in clotting of blood. Spontaneous bleeding, blood takes long time to clot.

WATER SOLUBLE VITAMINSVitamin ‘B1’ Whole cereal, wheat germ, green vegetables,

soya bean, milk, yeast, meat, sea food & unpolished rice.

Helps the body to oxidize food to release energy.

Beri-beri affects nervous system, muscles become weak causing cramps, pain, numbness & may lead to paralysis. Retarded growth in children.

Vitamin ‘B2’ Peas, beans, oil seeds, green vegetables, yeast, milk, liver, meat, eggs, fish.

Necessary for healthy skin, eyes and nerves.

Photophobia – eyes become sensitive to sunlight. Dry skin, sores on corners of mouth, tongue and lips.

Constituents of Food…..... contdVitamins

Name of VITAMIN Sources Functions Deficiency diseases

Vitamin Niacin B3, Nictonic acid

Cereals, yeast, milk, liver. Necessary for enzyme activities.

Pellagra – Skin lesions, rashes, diarrhoea

Vitamin ‘B6’ Whole grains, green vegetables, fish, meat, groundnuts, potato and tomato.

Necessary for amino acid and fatty acid metabolism.

Dermatitis, diarrhoea, dementia (mental sickness), characterized by 3D symptoms.

Vitamin Folic acid Green vegetables, sprouted seeds, cereals, eggs and liver.

Necessary for the production of RBC and nucleoprotein synthesis.

Haemoglobin content of the blood will drop. Number of RBC is reduced.

Vitamin ‘B12’ Milk, milk products, eggs, fish, meat and liver. Helps in formation of blood. Acute anaemia.

Vitamin ‘C’ Citrus fruits like lemon & orange, gooseberry (amla), guava, green leafy vegetables, papaya, tomato, sprouted grams.

Helps to bind the cells together and in the use of calcium by bones and teeth. Necessary for production of strong skin and collagen fibre synthesis.

Scurvy – symptoms – general weakness, bleeding gums and internal organs. Anaemia and swollen legs.

Constituents of Food…..... contdMinerals• Minerals play an important role in the metabolic activities of the body. They help in maintaining

acid-alkali balance in the cells of the body.• They are essential for maintaining normal tone of muscles, nerves and blood and also for

functioning of several enzymes.• Some of the major minerals required by the body are calcium, phosporous, potassium, sodium,

chlorine & magnesium. Other minerals required in traces are manganese, copper, zinc , iodine, cobalt and flourine.

CALCIUM –• It is the chief constituent of teeth and bones.• It occurs in larger quantities when compared to other minerals in the body. • It is essential for clotting of blood, functioning of cardiac muscles & for normal growth in children. • The deficiency of calcium in children leads to RICKETS. • Chief sources of calcium are milk, milk products, sesame seeds, green leafy vegetables, ragi and fish PHOSPHOROUS –• It occurs in the form of phosphate or phosporic acid in the cells.• It is also the chief constituent of teeth and bones along with calcium.• It takes part in various metabolic processes in ionic form.• Chief sources of phosphorous are milk, milk products, pulses, cereals, nuts, oil seeds, fish and meat.IRON –• Most of the iron present in the body is haemoglobin, a constituent of blood and muscles.• Iron functions as oxygen carrier in blood and for functioning of certain enzymes.• Deficiency of iron causes anaemia.• Chief sources of iron are green leafy vegetables, groundnuts, cereals and pulses.

Constituents of Food…..... contdIODINE –• The endocrine gland thyroid secretes a hormone called THYROXIN which is essential for normal growth

and development.• Iodine is essential for synthesis of THYROXIN.• Iodine deficiency causes a disease known as GOITRE.• The thyroid gland becomes swollen and affects the rate of metabolism.• Sea fish and other sea food contains iodine. SODIUM –• It is essential for cardiac muscle functioning and regulating acid-base balance in the body.• Common salt, milk, milk products, egg, meat and fish are the chief sources of sodium.POTASSIUM –• It is present in the body cells and RBC.• Just like sodium, it regulates acid-base balance in the body.• It influences muscular activity.• Chief sources of potassium are oil seeds, nuts, pulses, green leafy vegetables, fruits, cereals, eggs and most

of the food items.

WaterIt is the most essential part of the protoplasm in every cell.It makes upto nearly 60% to 70% of the body weight.Water is a universal solvent.Most of the nutrients dissolve in it and reach every cell.Althought it is not considered as a nutrient, it is essential for the survival of the cell. The water we drink to quench thirst is sufficient to provide the requirements of our body.

Constituents of Food…..... contdNutritional significance of water: Water is the medium for all metabolic activities and biochemical changes that takes place in the

body.Water is required for elimination of waste materials from the body in the form of urine and sweat.

It maintains the fluidity of blood and lymph so that they transport the materials from one part of the body to another.

It replaces the loss of fluids from tissues. It regulates the body temperature. It maintains the electrolyte balance in cells and tissues.Roughage• It is not a nutrient since it does not help in providing energy or building tissues.• However, it has to be an essential part of our food because it helps the normal functioning of the

digestive system.• Our body cannot digest polysaccharides like cellulose, hemicellulose, lignin and pectin which are

present in most of the food of plant origin.• Such fibrous substances collectively form the roughage part of the blood.• Cabbage, peas, carrot, turnips and fruits which have edible skins like apple, guava, peas, cereals &

pulses are the chief sources of roughages.Nutritional significance: They have the ability to absorb water. They combine with intestinal wastes making them bulky. This expands the intestinal lumen and stimulates the movement of waste in gastrointestinal tract. Thus it facilitates the elimination of intestinal wastes.

Balanced diet and energy requirementsBalanced diet and energy requirements: The quantity and nature of food we eat everyday is termed as diet. A diet which contains various nutrients in right proportions and include water and dietary fibres required by the

body is called a balanced diet. A balanced diet provides sufficient nutrients to maintain good health. However, the type of diet required for a person depends upon age, gender, size of the body and activity. It also depends on environmental factors. For instance, people living in warm climate require less food when compared to people living in cold countries. While planning a balanced diet, the energy requirement of the person and nutritional value of food must be the

criteria. We should select a variety of food items available everyday and make up a balanced diet. With should plan a balanced diet and follow certain principles. We must have timely eating habits. We must avoid the habit of eating junk foods because they neither provide us with nutrients nor help digestion. Hygeinic food with clean filtered drinking water taken at the right time and right quantity gives ensures good

health.

Food ManagementFood production in our country has increased tremendously in the past few decades.

• Modern scientific methods are being used to improve the yield and increase food production.

However, nearly 10% of the food goes waste because of unscientific storage practices.• Population explosion on one hand and wastage of food on the other hand have contributed to

shortage of food.

• Hence, the increased production of food has not yielded the desired beneficial effects.• Storage of food is as important as food production. Therefore, knowledge of proper storage

methods is essential.In the following slides, we will learn about the causes of food spoilage and some of the storage methods practised in our country.

Food management - Causes of food spoilageThe food grains, vegetables and fruits are grown seasonally. They have to stored and supplied throughout the year. Hence, the harvested food has to be stored in a scientific way and supplied to people.

FOOD SPOILAGE: The quality of food deteriorates if it is not stored properly. The food gets spoiled by micro organisms and pests and thereby the food is poisoned. This food is unfit for human consumption.The process of deterioration of food losing its nutritive value is called FOOD SPOILAGE.Spoiled food is dangerous to health. The toxins may even cause death.The factors responsible for food spoilage and wastage can be classified into 2 groups• Internal factors• External factors

Refer this chart for the various factors for food Spoilage.

Food SpoilageINTERNAL FACTORSMoisture content of food material:

Most of the food materials contain certain percentage of moisture in them.Fruits and vegetables contain higher percentage of moisture. All plant products respire during storage and produce heat.Several chemical changes occur in presence of moisture.Moisture and heat encourage the growth of micro organisms which spoil the food.Vegetables like onion, potato and grains sprout in the presence of moisture.

sprouted grains & vegetables

Rotten fruits

Hence the maximum amount of moisture permitted for every food item must be ensured before storage and suitable storage material must be used.For instance, moisture content in food grains such as rice, ragi, jowar & wheat should NOT be >14% during storage

Food spoilage….contdINTERNAL FACTORSActivity of Enzymes:

Enzymes are present in plant and animal cells.They are responsible for ripening of fruits, spoiling of fruits, vegetables and meat.The activity of enzymes continue even during storage period if conditions are suitable.Hence care should be taken to prevent enzymatic activity during storage.

EXTERNAL FACTORSStored food materials deteriorate sometimes due to factors in the surrounding environment. They are called as External factors.Temperature & Humidity:

The temperature favourable for the growth of microorganisms is between 20⁰C and 35⁰C.If food is stored below 12⁰C, the microbial activity will slow down and food will not be spoiled for sometime.Similarly, if moisture content in the food stuff is more, the growth of fungi is promoted. Hence food should be stored in a cool and dry place.

Storage structures:Storage structures have to be build using damp proof materials. So the attack of fungi is prevented.Sour fruits like oranges, lemon and other citrus fruits reacts with metal producing poisonous substances.Lead containers should also be avoided as Lead is poisonous.Hence different food materials should be stored in carefully selected suitable containers & storage materials.

Food spoilage….cntdEXTERNAL FACTORSMicroorganisms:

We’ve already learnt that activity of microorganisms is enhanced under certain conditions like favourable temperature and high moisture content.Microorganisms such as bacteria, yeast, fungi etc cause considerable damage to stored food materials. They also produce toxins which are harmful to human health.

Insect infestation:Its very common to find insects in stored food grains. It is known as insect infestation.Usually rice stored in rice bins contain rice moth. The white worms often seen in rice are larvae of rice moth.They damage the kernel of the rice grains and cause damage.The other common insects are pulse beetle and grain moth which attack pulses and grains.

Rodents and birds:Rodents like bandicoots, squirrels, rats and mice cause extensive damage to food grains.These rodents not only destroy the food but contaminate them with their faecal matter, urine and hair causing diseases to man.On an avg, a rat consumes 30 – 35 gm of food grains everyday.Birds eat and destroy large quantities of food grain before and after the harvest.They also damage fruits and vegetables.Sparrow, myna, pigeon, crow and parakeets are some of the common grain eating birds.

Food storage and preservationFood substances can be classified into 2 groups depending upon the length of the storage period.1. Perishable foods2. Non-perishable foods

Perishable foods are those that have short life.Milk,Milk products, vegetables, fruits, cooked foods, meat& fish are examples of perishable foods.Non-perishable foods are those foods that can be storedfor quite sometime without getting spoiled.Pulses, cereals & grains are examples of non-perishable foods.

METHODS OF STORING PERISHABLE FOODSPerishable foods can be stored for sometime without reducingtheir nutritive value using some scientific methods as follows.3. Cold storage and freezing 4. Dehydration5. Canning6. Pasteurization7. Chemical method8. Wrapping or coating method9. Irradiation method

Food storage and preservationCOLD STORAGE & FREEZINGCold storage: Storage of food in cold temperature in the range of 6⁰C - 8⁰C is called Cold storage. Vegetables, fruits, milk, milk products and cooked food are generally stored in this method. The domestic refrigerators work on this principle. The general metabolic rate of the food slows down at this temperature and microbial activity is also

reduced. The growth of bacteria and fungi on the food is prevented thus keeping the food fresh for

sometime.Freezing: If food is stored below 0⁰C, it is known as Freezing. Freezing totally prevents enzymatic action and microbial activity. Hence the food can be stored for a long time. This method is useful in transporting food to far away places which requires several days. Fruits, vegetables, meat, fish and other animal products are frozen, packed and transported.

DEHYDRATIONExcess of water contained in the food is removed using several methods. The nutritivevalue remains the same. Fruits like grapes and vegetables like potato and onion flakes can be preserved by this method. Dehydration is done using the following methods.Sun drying:Food material is exposed to sun light for drying. Different food materials are exposed to sunlight for different durations. Cereals and some fruits are dehydrated using this method.

Food storage and preservation….cntdVacuum drying:• The food is dried in a vacuum chamber.• It is used in dairy industries in the preparation of milk powder, cheese powder, ice cream and other milk products.Hot air drying:• Hot air is blown over food material.• Fruits like grapes and vegetables like potatoes, onion flakes are dehydrated by this method.CANNING• In this method, the selected food material is filled in clean, steamed containers under pressure and

sealed.• The sealed container is subjected to high temperature and then cooled.• This destroys all micro organisms. Hence the canned food can be preserved for long time.• Green peas, jams, jeelies etc are preserved using this method.PASTEURIZATION• Pasteurization involves boiling milk at 65⁰C for about 30 minutes and suddenly chilling it.• This process destroys most of the micro organisms.• However, curdling bacteria survive.• Hence milk has to be stored below 5⁰C.CHEMICAL METHOD• Certain chemicals like salt, sugar and sodium benzoate are used to preserve food substances.• It is known as chemical method of preserving food.

Food storage and preservation….cntd• High concentration of sugar minimizes the moisture content and thereby inihibits the growth of

bacteria.• Guava, orange, papaya, grapes and pineapple are preserved in concentrated sugar solution.• Chillies, mangoes, lemon and fish are preserved by Salting.

• Food preservatives like vinegar, citric acid, sodium benzoate, sodium or potassium meta bisulphate are used in preserving fruit juices, squash, jams, jellies, salads and pickles.

• This method is mostly used for domestic purposes on a small scale.

WRAPPING or COATING method• This method is used only for certain selected food substances like eggs and few fruits.• Eggs are preserved by applying a thin coat of oil on the shell.

IRRADIATION METHOD• This method of preserving food is a recent technique. Scientifically packed food is exposed to gamma

rays for a suitable duration.• The ionizing radiation penetrates through the packed food materials and destroys all the micro

organisms.• Fruits, vegetables, meat and several other food materials can be preserved by this method.• This method has not gained acceptance due to fears associated with ionizing radiations.

Food storage and preservationNon-perishable foods can be stored in following methods1. Dry storage2. Gunny bags storage grain silos

METHODS OF STORING NON-PERISHABLE FOODSDry Storage:• Cereals, pulses, grams, dry seeds, sugar, spices and flour are stored at room temperature. It is called

dry storage. • Grains are stored on a large scale in storage bins called grain silos. • The silos protect the food from moisture, pests and dust.• They also have inbuilt facilities to withdraw desired quantities of stocks. • Stuff can be periodically checked, fumigated, temperature can be controlled from time to time.• It is also protected against rodents and other pests.

Gunny bags:• Gunny bag is another age old, yet efficient method of storing non-perishable food materials.• The gunny bags should be clean and dry.• The packed bags are stacked one above the other such that there will be sufficient space for

periodic fumigation.

Responsibilities – Food preservationWhat did we learn so far ??????i. The methods of food preservation discussed in previous slides are all useful for bulk storage.ii. Certain simple methods of preserving food at domestic levels also help in avoiding wastage of food

materials.iii. Food storage and distribution are very important and it should be done through out the year.

iv. It is the responsibility of every one of us to take care not to waste food / food materials.

Now, you will be able to……… Give the definition of nutrition, nutrients and the basis of classification of nutrients. Acquire complete knowledge about balanced diet and malnutrition. Understand the nutritional significance of carbohydrates, fats, proteins, vitamins, minerals, water

and roughage. Identify the sources of various nutrients and select the suitable food to get a balanced diet

everyday. Be aware of the fact that the components of the diet and requirements differ from person to

person depending upon age, occupation, gender, location etc. Understand the harmful effects of eating junk food and drinking soft drinks at meal time. Good habits like taking fresh wholesome food and providing sufficient rest and sleep to the body. Understand that storing the food produced is as important as production of food. Identify the internal and external factors responsible for food spoilage and understand the various

method of controlling it.

NOTESWhat is CFTRI ?The Central Food Technological Research Institute (CFTRI), Mysore has standardised the method of preserving several perishable food substances.

Fruits like mangoes, sapota and banana are dipped in wax emulsion containing a small quantity of fungicide.

Spoilage of eggs can be prevented by getting the surface of eggs smeared with oil.

What are fumigants ?Fumigants are chemicals that evaporate slowly and kill the insect pests without causing damage to the food grains.Ethylene dibromide (EDB) and Aluminium phosphate are two commonly used fumigants.