• SCIENTIFIC STUDY OF FOODS
• MEAL PLANNING I
• MEAL PLANNING II
• BUYING OF FOODS
• FOOD PRESERVATION AND STORAGE
• KITCHEN EQUIPMENT AND UTENSILS

SCIENTIFIC STUDY OF FOODS

Home Economics JSS3

Week 1

Topic: SCIENTIFIC STUDY OF FOODS

Contents:

Characteristics of Food Storage

Characteristics of Protein

Characteristics of Carbohydrates

Characteristics of Fats and Oil

1. SCIENTIFIC STUDY OF FOODS

Food is any edible material, usually of plant or animal origin, that contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals, and is ingested and assimilated by an organism to produce energy, stimulate growth, and maintain life or life processes.

CHARACTERISTICS OF FOOD STORAGE

The various food nutrients differ from each other in their: –

1. Physical properties: These include their structural appearances and it may change when it is treated in certain ways.
2. Chemical properties: These include the chemical compositions of the nutrients. A chemical property is any of a material’s properties that becomes evident during a chemical reaction; that is, any quality that can be established only by changing a substance’s chemical identity. Or the behaviour of a substance when it undergoes chemical change or reaction.

2. CHARACTERISTICS OF PROTEIN

1. Proteins are made up of carbon, hydrogen and nitrogen
2. The elements arrange themselves in different combinations to form amino acids.
3. Proteins are digested by enzymes called protease
4. Most proteins are insoluble in water
5. Many proteins are coagulated by heat
6. Proteins are not easily destroyed by heat

EFFECT OF HEAT ON PROTEIN

The effect of most heat on protein is known as coagulation. The effect of dry heat on protein causes it to shrink, harden the outer part of the meat and seals in the juices.

TEST FOR PROTEINS

1. Million’s test: Place 2-3g of egg white in a test tube, add about 4ml of water and shake, then add 2.5mls of million’s reagent, observe a white precipitate that forms. Place the test tube in a beaker that is half filled with water, heat the water slowly, the precipitate turns red, indicating the presence of protein.
2. Biuret test: Place a small quantity of egg whit in a test tube and mix with a few drops of water. Add about 1cm³ of dilute caustic soda (NaOH), mixed well. Drop by drop add 1% copper (II) sulphate solution, shake well after each drop. A purple or violet colour indicates the presence of protein.

3. CHARACTERISTICS OF CARBOHYDRATES

1. The elements that make up carbohydrate are carbon, hydrogen and oxygen
2. These elements combine in different ways to form (a) simple sugars e.g glucose (b) complex sugars e.g lactose (c) starches e.g yam (d) cellulose found in vegetables
3. All sugars are sweet
4. Sugars are soluble in water
5. Starches are often stored as starch grains in plant cells.
6. The last products of carbohydrate digestion is glucose

EFFECTS OF HEAT ON CARBOHYDRATE

• The effect of dry heat on sugar:- A brown honey like substance is formed. This is called Caramel. This process of production of caramel is known as Caramelization.
• The effect of moist heat on sugar forms a syrup.
• The effect of dry heat on starch- A light brown color will be observed. The product is called Dextrin. The process is known as Dexterinization.
• The effect of moist heat on starch – The starch will swell and a jelly substance is formed. The process is called Gelatinization

TEST FOR SIMPLE SUGAR

1. Fehling’s test:- Place 6ml of 6% sugar solution in a test tube. Add 6mls of Fehling’s solution into the sugar solution, place the tube into a beaker half filled with water, heat the beaker gently to boil. An orange or brick red precipitate is formed, this shows the presence of a simple sugar.
2. Benedict’s test: Place about 6ml of 6% sugar solution in a test tube, add equal quantities of benedict’s solution, boil as it is done with the Fehling’s test, allow to stand. A red, orange or yellow precipitate is formed.

TEST FOR STARCH

Cut a thin slice of yam or potato, drop 1-2 drops of dilute iodine solution on the cut slice of yam. The yam turns blue-black in color. This shows the presence of starch.

4. CHARACTERISTICS OF FATS AND OIL

1. They contain high proportion of carbon and hydrogen but very little oxygen
2. They are bad conductors of heat
3. Fats and oils are insoluble in water but soluble in ether
4. They are broken down into fatty acids and glycerol
5. Fats are solids at room temperature, oils are liquid at room temperature
6. When fats and oils are exposed to air for prolonged period they become rancid

TEST FOR FATS AND OIL

1. The grease spot test:- Rub a little palm oil on a blotting paper, hold up the paper. A translucent patch is formed by the oil mark and shinning patch is observed in the place stained by the oil.
2. Sudan III test:- Place a small quantity of groundnut paste in a test tube, add a few drops of sudan III solution. A distinct red coloration is produced.

Assessment

• List four characteristics each of Fats and oil, Carbohydrates and Protein

MEAL PLANNING I

Home Economics JSS3

Week 2

Topic: MEAL PLANNING I
Contents:

Factors that Influence Meal Planning

Guidelines for Meal Planning

1. MEAL PLANNING

Meal planning can be defined as taking the time to plan nutritious meals  for a specified time . It is the process of planning the type of food the family wants. To plan healthy family meals, the groups and classes of foods must be put into consideration.

Meal planning is also the implementation of the principle of nutrition in one’s daily diet in an appetizing manner. Once a meal plan is drawn up, corresponding ingredients can be purchased for the specified meals on the plan.

To enable a meal planner prepare meals that will supply the nutritional needs of every member of the family, it is necessary to eat balanced meals. A balanced meal is one that contains all food nutrient in correct quantities for a given person. Meal planning involves choosing a menu or a list of foods that will be included in a meal.

Balanced Meal: A balanced diet includes three meals that together account for the recommended daily servings from each group every day. By ensuring that half the foods consumed in a day are fruits and vegetables and the other half are made up of grains and protein with a small amount of low-fat dairy, individuals can ensure a diet that is balanced and healthy . This kind of meals contain all six classes of foods.

Factors that influence meal planning

1. Age of Family Members: The age of each family member influences his/her nutritional needs. These include children, adolescents, adults and the aged.
2. Occupations or Activities of family members: The work a person does influences his food needs, for instance a manual worker will require more energy foods than sedentary worker
3. Health conditions of family members: Certain foods are not suitable for certain health conditions.
4. Size of the family: The size of the family will determine the quantity of meal to plan for.
5. Seasons of the year: Most food stuffs are seasonal. Foods in seasons are cheaper, fresher and tastier than when they are out of season. Different foods are available for different seasons.
6. Money Availability: The quantity or type of food to plan for, depends on the income of a family.
7. Time Availability: The planner should consider the time available for her to prepare and serve the meal.

Guidelines for meal planning

1. The meal must contain all necessary food nutrients.
2. Provide for nutritional needs of all family members in the meal plan.
3. Avoid monotony by varying foods.
4. Make use of foods in season.
5. Buy good quality foods.
6. Plan meals several days ahead of time so as to save money and time.

Assessment

• Define the term Meal Planning and a Balanced meal
• State five factors that affect meal planning

MEAL PLANNING II

Home Economics JSS3

Week 3
Topic: MEAL PLANNING II
Contents:

Guidelines for providing Children’s Meals

Guidelines for Providing Meals for Invalids

Vegetarians

NUTRITIONAL NEEDS OF DIFFERENT PEOPLE IN THE FAMILY

• Young children (in fact 0-1 year and toddlers 1-2 year(s) young children are growing rapidly. They are also very active; they require food for growth and their activities.

GUIDELINES FOR PROVIDING CHILDREN’S MEALS

1. The food must be rich in protein, energy foods, minerals and vitamins.
2. Their food should be rich in milk, meat, fish, eggs, legumes,
3. Meal times should be regular.
4. Young children’s meals must be cooked by the most easily digested methods.
5. An excessive consumption of sweets and candies that may lead to tooth decay should be avoided
6. Meal time for children should be a pleasurable time.
7. Adolescents: It is a period of rapid growth and development. They require adequate diet to enable them to cope with the development changes, they undergo. Adolescent boys need larger quantity of food while the girls require increased intake of food rich in iron as this will help to replace what they lose monthly during menstruation.
8. The adult: Members of this group have reached maturity and stopped growing. They therefore require foods for energy and maintenance rather than for growth. An adult’s diet should be balanced. It should be suitable for his work, health and age.

SPECIAL GROUPS OF ADULTS

• Manual workers/laborers: They burn a lot of energy and so their diet should be high in energy giving foods, for example, farming, bricklayers
• Sedentary workers: They do not require much energy giving foods in their diet. Their job usually requires sitting down e.g receptionist
• Pregnant woman: These must provide for the nutritional needs of the foetus. They therefore require extra nutrient in addition to the balanced diet. She needs to increase her intake of protein, mineral, vitamin and water. Excess carbohydrate and fatty foods should be avoided to prevent overweight
• Lactating mother: This is a woman who is breast feeding a baby. She requires extra nutrient and an adequate diet to produce enough breast milk.
• The elderly/aged: this group no longer spends much energy as a result of reduction in physical activities. They require less energy-giving foods in their body building and protective foods should be maintained. Their food should be soft textured for easy chewing and digestion
• Invalids and convalescents: An invalid is a person who is sick but is in the process of gradual recovery after the illness.

GUIDELINES FOR PROVIDING MEALS FOR INVALIDS AND CONVALESCENTS

1. Follow the doctor’s orders strictly
2. Serve foods that are easily digested
3. Serve adequate meals especially more of proteins, fruits and vegetables for body building and protection.
4. Serve meals at regular time daily
5. Serve attractive and appetizing meals
6. Give plenty of fluids
7. Do not use strong spice in preparing meals

VEGETARIANS

These are people who do not eat animal flesh. They get their proteins from plant sources. Vegetarianism is the practice of abstaining from the consumption of meat (red meat, poultry, seafood and the flesh of any other animal), and may also include abstention from by-products of animal slaughter.

THREE TYPES OF VEGETARIANS

1. Strict vegetarians: These people are also known as vegans. They do not eat flesh of animals nor any animal products. They eat only vegetables or plant proteins.
2. Lacto vegetarians: These are people who do not eat the flesh of animals or eggs but they take milk and diary products together with vegetable.
3. Lacto-ovo vegetarians: These are people who do not eat the flesh of animals but take milk and milk products and eggs with vegetables.

Assessment

• Name three types of Vegetarians
• Name the special groups of Adults

BUYING OF FOODS

Home Economics JSS3

Week 4
Topic: BUYING OF FOODS

Contents:

Importance of Buying Good Quality Foodstuffs

Guidelines for Purchasing Good Quality Foodstuffs

Methods of Purchasing Food

A. BUYING OF FOODS

Food is very important for good health. It is necessary that family food purchase be carefully planned, carried out and properly stored to prevent wastage and ensure that food is safe and hygienic.

IMPORTANCE OF BUYING GOOD QUALITY FOODSTUFFS

1. Good quality foodstuffs are fresh and wholesome
2. Their nutrient contents are still intact
3. They keep well in storage
4. They are not yet attacked by food spoilage organisms
5. They are appetizing and taste good
6. They are economical because there is little or no wastage
7. They have good appearance

B. GUIDELINES FOR PURCHASING GOOD QUALITY FOODSTUFFS

1. Consider the nutritional needs of each family member
2. Plan meals for several days at a time
3. Prepare a good shopping list of foodstuffs to be purchased
4. Ensure that there are adequate storage facilities for the foodstuffs to be purchased
5. Buy good quality food stuffs
6. Buy foods that are in season
7. Avoid impulse buying
8. Compare values and prices in different stores.

C. METHODS OF PURCHASING FOOD

There are two methods of purchasing food.

1. Bulk buying
2. Piece meal

BULK BUYING

This involves buying a large quantity of different foodstuffs at a time.

Advantages of Bulk Buying

1. Foods are cheaper when in season
2. It saves money, time and energy if there is effective storage
3. It helps her to manage her family resources well
4. It helps the house maker to plan her budget and avoid the habit of buying what she never bargained for
5. Food is always available for family members

Disadvantages of Bulk Buying

1. It may result in poor management and careless usage of foodstuffs
2. It encourages wastefulness
3. Deterioration of foodstuffs is likely to occur when there is no proper storage facility

BUYING PIECE FOOD

This involves buying small quantities of foodstuffs at a time.

Advantages of buying Piece Food

1. One does not need a large sum of money to buy foodstuffs
2. You do not have to go round from place to place comparing prices
3. It is better for the house maker who lacks storage facilities
4. It does not encourage wastefulness

Disadvantages of buying Piece Food

1. It wastes time, money and energy
2. It does not help much in the family budget
3. Food is not always available and this may cause embarrassment in an emergency
4. It makes the management of family resources inadequate

Assessment

• State the importance of buying good quality foodstuffs
• State 5 advantages and disadvantages of buying piece food

FOOD PRESERVATION AND STORAGE

Home Economics JSS3

Week 5
Topic: FOOD PRESERVATION AND STORAGE
Contents:

Food Preservation

Food Preservation Methods

Food Storage

A. FOOD PRESERVATION

Food preservation is the caring or treating food in a way that it will keep in good condition for a long period of time or for future use. Food preservation usually involves preventing the growth of bacteria, fungi (such as yeasts), or other micro-organisms into food. Food preservation is the process of treating and handling food to stop or slow down food spoilage, loss of quality, edibility, or nutritional value and thus allow for longer food storage.

REASONS FOR PRESERVING FOOD

1. Some foods are seasonal that is they are plenty at a time and not available at other periods
2. In some farming communities, food is produced in abundance and need to be preserved for sales in cities or during scarcity
3. Preservation is also necessary to prevent food spoilage.
4. Save money by buying in bulk and seasonally.
5. Convenience – Ready to serve in minutes.

B. FOOD PRESERVATION METHODS

1. Solar or sun dry: This is a very effective way of preserving some vegetables e.g maize, beans, yam e.t.c
2. Smoking: Foods such as fish, meat and some root crops can be preserved by smoking
3. Freezing: This is a method of preserving food in which it is put in refrigerator so that it becomes frozen very quickly e.g meat, fish, tomatoes e.t.c
4. Canning: This is preservation by sealing food inside an air tight can and applying heat e.g. fruits and vegetables
5. Other forms of preservation are Bottling, Pasteurization, Salting, Heating e.t.c

TYPES OF FOOD WE STORE:

1. Non-perishable foods or dry foods
2. Perishable foods or fresh foods

Non- perishable foods or dry foods: Are those foods that do not spoil easily. These can be keep for a long time if stored properly e.g flours, rice, sugar, cereals e.t.c

Perishable foods or fresh foods: Are those foods that can spoil easily e.g fresh meat, fish, vegetables, fresh tomatoes e.t.c

C. FOOD STORAGE

Food storage involves keeping preserved or purchased food in safe condition and suitable facility for use.

Storing of food has several main purposes:

• Storage of harvested and processed plant and animal food products for distribution to consumers
• Enabling a better balanced diet throughout the year
• Reducing kitchen waste by preserving unused or uneaten food for later use
• Preserving pantry food, such as spices or dry ingredients like rice and flour, for eventual use in cooking
• Preparedness for catastrophes, emergencies and periods of food scarcity or famine

FOOD STORAGE FACILITIES

Proper food storage requires the use of good storage facilities. Storage facilities include plastic containers, food cupboards, larders, shelves, rack, refrigerators and deep freezer.

REFRIGERATOR

A refrigerator is any appliance which removes heat from things (e.g foods) and keeps them cold. Refrigerator is the process of keeping food cold, often in a refrigerator

TEMPERATURES IN THE REFRIGERATOR APARTMENTS

1. The Freezer compartment: This is ice-cold. It is for storing very perishable foods
2. The Top-most shelf: This is nearest to the freezer. It is suitable for cooked food
3. Middle shelf: This is next to the vegetable crisper. It is suitable for drinks, raw foods, bread e.t.c
4. Vegetable crisper: This is the lower apartment. It is suitable for raw-fruits and vegetables.
5. Door of the refrigerator: Storage spaces for such items such as eggs butter, cheese e.t.c

Assessment

• State 4 reasons for preserving food
• List preservative methods that you know
• What are the purposes of storing food

KITCHEN EQUIPMENT AND UTENSILS

Home Economics JSS3

Week 6
Topic: KITCHEN EQUIPMENT AND UTENSILS
Contents:

Factors affecting the choice and use of cooking utensils and equipment

General care for Kitchen equipment and Utensils

KITCHEN EQUIPMENT AND UTENSILS

Kitchen tools are those materials used in day to day activities in the kitchen while equipment are those ones that are bigger in size than cooking tools. A good knowledge of equipment and utensils used in food preparation is necessary to assist us in choosing appropriate methods of cooking a particular type of food with a suitable equipment/ utensils. Much energy, time and labor can be saved if appropriate utensils are involved in food preparation. Those equipment and utensils which are powered by electricity or gas are kitchen appliances. A kitchen utensil is a hand-held, typically small tool that is designed for food-related functions.

FACTORS AFFECTING THE CHOICE AND USE OF COOKING UTENSILS AND EQUIPMENT

1. Choose the right type of utensils or equipment for a specific job.
2. The equipment should be suitable and convenient for the user
3. It should be durable, efficient and should be able to save time, labor and money
4. It should be simple to use and clean
5. If it has a lid, it should fit closely
6. The sauce pans and pots should have heat resistant and insulating handles.
7. The size of the family should be considered as well as the money available for the purchase of such utensils
8. The materials from which the utensils are made should not rust easily.

The cooking utensils and equipment can be classified into:

Large equipment: e.g Gas and electric cookers, Steamers, fish fryers, Sinks, table e.t.c

Mechanical equipment: e.g. Mixers, refrigerator, dish washers, blenders e.t.c

Utensils and small equipment: e.g. pots, pans, whisks, bowls, spoons, knife, forks e.t.c.

GENERAL CARE FOR KITCHEN EQUIPMENT AND UTENSILS

1. Each piece of kitchen equipment and the utensils has to be used correctly to obtain the best results
2. Follow the manufacturer’s manual for the use and care of each equipment
3. Preserve the manual as longs as the equipment in use
4. Repair appliances and utensils promptly
5. Store kitchen equipment and utensils properly

Examples of Some Kitchen Utensils and Equipment

Rolling pin: A tool used to flatten dough for rolls, pizza, cookies, chin-chin e.t.c

Rolling Pins

Strainer or Sieve: A wired mesh container that is used to strain liquids away from solid ingredients or to separate and aerate dry ingredients like flour and powdered sugar, cassava flour (garri) e.t.c. There are two types, one made of metal and the other plastic.

Sieve

Plastic Sieve

Grater: A cutting tool used to shred or grate foods like potatoes, cabbage, carrot, cheese or if the surface is fine, to zest lemons or ginger.

Electric Grater

Grater

Blender: Used to cut food and ice into very small pieces and to make soft foods (such as fruits) into a liquid.

Blender

Assessment

• Mention some of the factors affecting the choice and use of cooking utensils and equipment
• Give four general care for kitchen equipment and utensils