Concepts of Nutrition and food Nutrients
Human Nutrition is the provision to obtain the essential nutrients necessary to support life and health.
Are several types of food substances that are needed by the human body for itsproper functioning.
The basic food substances include proteins, carbohydrates, lipids, vitamins,minerals, roughage and water.
Different Types of Food Substances and their Functions in Human Body
Identify different types of food substances and their functions in human Body
These are substances, which contain elements oxygen and nitrogen.
Foods such as Meat, liver, eggs, beans, milk, cheese, peas, groundnuts and mushrooms are good sources of protein.
Carbohydrates are mainly made of carbon, hydrogen and oxygen
Foods such as maize, rice, bananas, potatoes, cassava, wheat (bread, cake) and yams are rich in carbohydrates.
These are compounds of carbon, hydrogen and oxygen. They are insoluble in water. Lipids are made up of fatty acid and glycogen
Foods such as fish, nuts, seed oils, avocados and olives are good sources of lipids.
Vitamins are chemical substances in small amounts that are used to maintain thebody.
Vitamins can be grouped into two categories: water-soluble and fat-soluble vitamins.
Fat-Soluble Vitamins can be stored in the body. Examples of fat-solublevitamins are Vitamins A, O, E and K
Water-Soluble Vitamins are not stored in the body. Vitamins B and C are water soluble.Vitamin B is of various forms, namely Vitamin B1, B2, B6 and B12.
SOURCES, FUNCTIONS AND SIGNS OF VITAMIN DEFICIENCIES
Certain mineral elements are vital for the proper functioning of the body. Someare required in relatively large quantities and therefore called macro mineralsand others are required in very small quantities and are referred to as micro
Macro minerals include calcium, phosphates, potassium, iron, zinc, sodiumchlorine and magnesium.
Micro minerals include iodine, fluoride, manganese and copper.
Examples of minerals, their source and their function in the body
||SIGN OF DEFICIENCY
||Milk,Cheese,eggs andgreen vegetables
||– Helps build strong bones and teeth- Important inclotting of blood
||– Weak bones- Bleeding easily
||Meat, Milk,Fish, Eggs and nuts
||– Builds bones and teeth- Helps in muscle and nerve activity
||– Poor bone and teeth formation
||Peanuts,bananas,orange juice and green beans
||Needed for nerve and muscle function
||– Poor muscle contraction
||Liver,kidney,beans and green vegetables
||Essential for making hemoglobin
||Helps to heal wounds
||– Skin problems
||extrac tsand crab
||– For nerve and muscle activity
||– Muscle cramps
||Formation of hydrochloric acid in the stomach
||– Poor digestion of protein
||Spinach,pumpkin seeds, black beans
||– Relaxation of nerves and muscles- Strengthening of bones
||– Muscle weakness- Irregular heartbeat- Weak bones
||Meat, fish and liver
||Activation of enzyme
||– Anemia- Bone and joint problems
||Kidneys,liver, tea,coffee, nuts and fruits
||Formation of bones
||– Nausea- Dizziness- Loss of hearing
||Iodized table salt and sea food
||Production of thyroid hormones which regulate growth
||– Goitre (enlarged thyroid gland)
– This is dietary fiber that is obtained from the indigestible parts of plants.
SOURCES OF ROUGHAGE
Foods such as fruits, beans, cabbage, spinach, cassava, and whole baked potatoesare good sources of roughage.
FUNCTIONS OF ROUGHAGE
It helps in the passage of food and feces through the gut by aidingcontraction of the gut muscles
This is a compound containing element hydrogen and oxygen
SOURCES OF WATER
Rainfall, Rivers, Springs etc.
FUNCTIONS OF WATER
Explain the concept of balanced diet in terms of food quality and quantity
Meaning of balanced diet:A balanced diet refers to food containing all types of food nutrients in the correctproportions. We should eat a diet low in fats, sugars and salts but high in protein,carbohydrates, vitamins, minerals and roughage. More importantly we shouldtake in large amounts of water.
IMPORTANCE OF A BALANCED DIET
In order for the body to function properly, different food substances are requiredto do different works for example:
Carbohydrates provide energy
Vitamins needed to keep the body healthy
Minerals are needed for protection against diseases
Water is a universal solvent
Nutritional Requirement for Different Groups of People
Explain nutritional requirement for different groups of people
Outline different types of nutritional deficiencies and disorders in human beings
This is the condition, which occurs when one fails to feed on a balanced diet. Itmay be too little or eating only one type. These deficiencies and disordersinclude obesity, rickets, kwashiorkor, marasmus and anorexia nervosa.
These are conditions of ill health in a person, which arise as a result of lifestyle.
The Causes, Symptoms, Effect and Control Measures of Nutritional Deficiencies and Disorders
Explain the causes , symptoms, effect and control measures of nutritional deficiencies and disorders
Digestive System in Human
DIGESTIVE SYSTEM IN HUMAN BEINGS
The digestive system of human refers to the human alimentary canal and theorgans and glands associated with it.
Parts of the Human Digestive System and their Adaptive Features
Identify parts of the human digestive System and their adaptive features
The main parts are:- Mouth, Oesophagus, stomach, small intestine, (duodenumand ileum), large intestine (colon) and rectum.
ADAPTATIONS OF STOMACH TO ITS MODE OF FUNCTION
Digestion is the process by which food is broken down into a form that can beabsorbed and used by the body.
Digestion process involves two processes, which are mechanical break down offood and chemical break down of food. The mechanical break down of food takesplace in the mouth where the food is chewed by teeth so as to reduce it into smallpieces.
Digestive enzymes achieve chemical break down of food. The digested food isabsorbed and assimilated in the body.
The digestion process starts in the mouth where food is mechanically brokendown by teeth. The presence of food in the mouth stimulates the salivary glandto produce more saliva.
FUNCTIONS OF SALIVA
DIFFERENCES BETWEEN HUMAN DIGESTIVE SYSTEM AND RUMINANTS’DIGESTIVE SYSTEM
Common Disorders and Diseases of the Human Digestive System
Outline common disorders and diseases of the human digestive System
DISORDERS AND DISEASE OF THE DIGESTIVE SYSTEM
Explain causes, symptoms, effects and control measures of common disorders and diseases of the human digestive system
- Micro nutrients or minerals
- Macro nutrients
Macro nutrients are minerals that are required in a large quantity for the plant growth.
Nitrogen, phosphorus, potassium, sulphur, sodium, magnesium, carbon, hydrogen,and oxygen.
Micro nutrients; these are nutrients that are required in small amount for the plantgrowth.
They include; iron, cobalt, fluoride, silicon, iodine, copper and zink
The Roles of Essential Elements in Plant Nutrition
Investigate the roles of essential elements in plant nutrition
The role of essential mineral elements in plant nutrition
||Protein synthesis Manufacture of chlorophyll Promotes normal plant growth
||Leaves become pale green, yellow, small leaves, thin weak stem and stunted growth
||Promote root and branch growth Protein synthesis and energy release in respiration
||Poor growth of roots,leaves and branches Leaves become reddish purple
||Used during photosynthesis and protein metabolism in younger lives
||Yellow leaves with dead spots especially at marginsand tips
||Promotes normal plant growth and cell wall formation
||Poor root growth Death of growing regions
||Yellowing of leaves
||Stunted growth Yellow patchers on leaves
The Concept of Photosynthesis
Explain the concept of photosynthesis
Photosynthesis is the process where by green plants manufacture their own food by using light energy produced from the sun. photosynthesis takes place in plants especially in leaves so as to make their own food by the presence of different factors.
FACTORS FOR PHOTOSYNTHESIS
Chlorophyll, corbondioxide, sunlight energy, mineral salts, temperature and water.Equation for photosynthesis:
The Structure of the Leaf in Relation to Photosynthesi
Describe the structure of the leaf in relation to photosynthesis
The petiole or leaf stalk attaches the leaf to the branch or stem. It keeps the lamina inposition that will enable it to get a maximum amount of sunlight. The lamina has alarge surface area, thus maximizes the absorption of light energy and carbondioxide.The lamina is also thin so that carbondioxide and light energy diffuse over a shotdistance to reach cells.
The mid rib and veins contain xylem and phloem. Xylem vessels transport water andmineral salt to the leaf. Phloem vessels transport manufactured food to other parts ofthe plant.
The Process of Photosynthesis
Explain the process of photosynthesis
It takes place inside the cell organelles known as chloroplasts. Photosynthesis takesplace in two stages the light stage and the dark stage.
The Importance of Photosynthesis in the Real Life Situation
Outline the importance of photosynthesis in the real life situation
Importance of photosynthesis in daily life:
All organisms which are heterotrophy depend on auto-trophy as source of food.
Living organisms depend on oxygen for their aerobic respiration produced during photosynthesis
. Photosynthesis convert light energy into chemical energy which is used by other organisms
. Humans depend on photosynthesis for the energy containing fossil fuel which have developed over a millions of year.
Properties of Food Substance
The Basic Food Substances and Their Properties
Mention the basic food substances and their properties
Is the kind of food substance nutrients made up of carbon, hydrogen, and oxygen.Example: cassava, maize, rice etc.
Monosaccharide is also known as simple sugar. They include glucose, fructose andgalactors. These sugars dissolve in water and form sweet solutions. Monosaccharideare reduced sugar. The general formulae for monosaccharide is (CH2O)n
Where “n” represents a number of carbon atoms and have a value between 3& 6.Example the formulae of glucose is (C6H12O6)
This is the kind of carbohydrate which is formed when two monosaccharidemolecules combine.
Two glucose molecules combine to form maltose.(C6H12O6) + (C6H12O6) condensation – C12H22O11+ H2Osome disaccharide are reducing sugars example lactose and maltose , other are nonreducing sugar example sucrose
Is the type of carbohydrates formed by condensation involving severalmonosaccharideExample starch, chitin etc
Properties of polysaccharides:
- They are not soluble in water
- They are non reducing sugar
- . They are not sweet
- When put in water they form suspension
Common Reagents and Chemicals used to Determine Food Properties
Identify common reagents and chemicals used to determine food Properties
TEST FOR CARBOHYDRATES
|Dissolve the food sample in water Add an equal amount of Benedict solution to the solution
|| Food sample dissolveColor change from blue to green to orange,yellow and finally brick red
||Reducing sugar is present
|Dissolve the food sample in water to getsolution Put 2 cm of a solution obtained in a test tube Add 1 cm of HCL acid
|| FIZZING COLORCHANGE FROM BLUE,GREEN,YELLOW,orange and finally brick red
||Non reducing sugar is present
|Boil the mixture Allow the mixture to cool Add small amount of sodium hydroxide,shake the test tube after every additional continue until fizzing stops Add 2 cm of Benedict solution then boil the mixture
|| FizzingColor change from blue, green to yellow to orange and finally brick red
||Non reducing sugar is present
|TEST B FOR STARCH Add small amount of food sample solution in a test food.Add few drops (2-3)of iodine solution in the food sample
||Color change from blue to black
||Starch is present
Food Tests for Reducing Sugars, Non Reducing Sugars, Starch, Proteins and Lipids (Fats and Oil)
Carryout food tests for reducing sugars, non reducing sugars, starch, proteins and lipids (Fats and Oil)
Food Processing, Preservation and Storage.
The Concept of Food Processing , Food Preservation and Food Storage
Explain the concept of food processing , food preservation and food storage
Food processing refers to all the ways in which food is treated in order to make itedible, appetizing and safe to eat or to keep it fresh for a long time.
Some of activities involved in food processing are;
- Picking, sorting and washing fruits and vegetables
- Cooking by boiling steaming, roasting backing or frying
- Converting raw materials into other products for example making cheersfrom milk or sugar from sugar cane
Food preservation refers specifically to the methods of food processing that areused to prevent food from spoiling or going bad
Methods of food preservation
Keeping out micro organisms for example by canning or bottling
Using high temperature to kill microorganisms that cause spoilage eg.By pasturalization and boiling
Using very low temperature to slow down the growth of microorganisms for example refrigerationiv.
Irradiation which is by using radiations such as gamma rays to killmicro organismsv
Eliminating the moisture that is needed for growth of micro organismfor instance by drying, salting, smoking etc
Adding chemicals such as salt sugar, carbon monoxide to preventphysical changes in food
Refers to the methods used to keep or reserve of food for future use. Foodstorage can be done on a small scale at the family level for example in afamily granary or food store. Or large scale for large populations e.g ingovernment stores of grains.
The Importance of Food Processing, Preservation and Storage
Explain the importance of food processing, preservation and storage
The following are the importance of food preservation
prevents wastage of food
it saves money by preventing spoilage of food
maintains the quality of food
prevents the growth of micro organisms that can cause illness
improve the flavor of food
removes armful toxins and micro organisms from food
makes food available even where they are not in season
enables transportation of delecate and perishable food such as milk andfruit over long distance
Traditional and Modern Methods of Processing, Preserving and Storing Food
Differentiate between traditional and modern methods of processing, preserving and storing food
They are two methods of food processing and preservation which are;
- traditional methods
- modern methods
These are methods used to process and preserve food which doesn’t require the use oftechnology. The following are the traditional ways.
It involves additional of substances such as salt, sugar, spaces and vinegar toanimal foods, moist meat and fish. Curing removes water making itunavailable for the growth of microorganism it also improve the taste of food.Sausages, becon and curried beef are made by curing meat.
DRYING IN THE SUN
Thus method is used to preserve rice, maize, cloves, banana, beans, peas,meat, fish etc.Here food is left for long time on the sun in order to reduce its moisturecontent. Reducing the amount of water in food discourages the growth ofmicroorganisms. Some food such as banana and cassava are cut into smallpieces to fasten the process.
Smoking is the traditional method which is used to reduce moisture content offood to prevent growth of microorganisms. Grains, meat, fish can be driedslowly over the smoking wood fire
Traditional methods of cooking are simple and include boiling, steaming,backing, in hot hash and roasting. These processes help to soften food,improve flavor and preserve food. Example potatoes, bananas, and maize canbe boiled before being dried.
STORAGE IN GRANARIES AND PITS
Dry grains are stored in granaries which are usually raised above the ground.The grains are sometimes mixed with neem leaf ash or groundnuts oil to further prevent attack by microorganisms.Granaries keep grains safe from insects rodents and birds. Example harvestedyams, potatoes and cassava can be stored in large pits in the ground after drying.
ADVANTAGES OF TRADITIONAL METHODS OF FOOD PROCESSING ANDPRESERVATION AND STORAGE
Is the temporary storage of food at low temperature of up to 4 centigrade inorder to slow down the growth of microorganisms. Freezing involves storingfood at very low temperatures in order to stop the growth of microorganisms .frozen food can be kept for months.Food that can be refrigerated include milk, fresh fruits, vegetables, juice andbutter. Freezing is mostly used for meat, fish, fruits and vegetables.
Thus method of preservation was named after its inventor Louis Pasteur. Itinvolved heating food to a very highest temperature for a short time in order tokill the micro organisms that can cause spoilage.Pasteurization maintains the nutrients content and flavor of food. Examples of food that can be pasteurized are milk and fruity juice.
In this method, food is preserved by heating it in airtight vacuum, sealedbottles or cans. The container is filled with food then the air is pumped out to form a vacuum. The container is sealed and heated to kill microorganisms and enzymes but not enough to overcook the food. Food that can be bottled or canned include tomatoes, fruits, juice, beef, fish and packed beans. Bottled or canned food can be kept for months or even years.
This method involved the use of chemicals such as sodium benzoate, sodiumchloride, and vinegar are added to food to slow down the growth of microorganisms. This is commonly done to pressure fish and meat
Food is dried by using either hot blast of air from a vacuum drayer. Afterdrying the food is then sealed in moisture –proof containers.
Is the modern method which involve the use of rays of energy to stop thegrowth of microorganisms in stored food. Example in onions, beans andpotatoes. This makes food last longer. It also prevents sprouting in onions andpotatoes.
ADVANTAGES OF MODERM MOTHODS
Food can last for many months and even a year
Modern methods can process, preserve, and store large variety of food.
They are advanced technology bused in fast and can handle huge quantities offood.
The chemicals used can be harmful if eaten in excess
These advanced technology involve means where they are used only in certain areas for instance refrigeration requires electricity.
The process used for example canning and pasteurizing require special skills.
Sometimes nutrients are lost thus lowering the nutritional value of food
DIFFERENCES BETWEEN TRADITIONAL AND MODERN METHODS OF FOOD PROCESSING AND PRESERVATION
|Less cost full
||High cost full
|It involves the use of low technology
||It involves the use of advanced technology
|It processes and preserves food for a limited amount of time
||Preserves food for months and evenyears
|It uses local materials to process and preserve food It is used by most people
||It uses chemicals to process and preserve foodIt is used by few people
|It select type of food to be processed and preserved
||It is not selective