Lesson Notes By Weeks and Term - Senior Secondary 2

Preservation of foods

Term – 3rd Term

Week: 2

Class: Senior Secondary School 2

Age: 16 years

Duration: 40 minutes of 2 periods each

Date:       

Subject:      Food and Nutrition

Topic:-       Preservation of foods

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to:            

  1. Define food preservation
  2. Give reasons for the preservation of foods
  3. Outline the causes of food spoilage
  4. State and explain the classes of food according to their moisture content

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

PRESENTATION

TEACHER’S ACTIVITY

STUDENT’S ACTIVITY

STEP 1

INTRODUCTION

The teacher reviews the previous lesson on convenience foods

Students pay attention

STEP 2

EXPLANATION

She defines food preservation. She gives reasons for the preservation of foods

Students pay attention and participates

STEP 3

DEMONSTRATION

She outlines the causes of food spoilage. She states and explains the classes of food according to their moisture content

Students pay attention and participate

STEP 4

NOTE TAKING

The teacher writes a summarized note on the board

The students copy the note in their books

 

NOTE

PRESERVATION OF FOODS

Food preservation is the caring for or treating food in such a way that it will

be kept in good condition for a long period of time.

 

REASONS FOR PRESERVING FOOD

  1. To prolong its shelf life.
  2. To prevent its spoilage to prolong its shelf life.
  3. To avoid wastage especially when they are in season.
  4. To allow foods in off- season to be used.
  5. To have a variety of food available for an emergency situation.
  6. To eliminate the purchase of food when they are most expensive.
  7. To introduce variety into the family menu.

 

CAUSES OF FOOD SPOILAGE

Food spoilage usually refers to undesirable changes taking place in food

which eventually leads to rejection and therefore to wastage. The following

are causes of food spoilage;

  1. Actions of micro-organisms e. g. bacterial yeast and moulds.
  2. Insect.
  3. Food enzymes.
  4. Chemical reactions in the food.
  5. Physical changes due to freezing burning, drying, pressure and so on.

 

CLASSIFICATION OF FOOD ACCORDING TO THE MOISTURE

CONTENT

  1. PERISHABLE FOOD OR HIGH MOISTURE FOODS:- These are foods which begins to spoil almost immediately unless preserved in some ways because of their high water content. Examples of such foods are milk, meat, fish, sea foods, fruits and vegetables.
  2. SEMI- PERISHABLE FOODS OR INTERMEDIATE MOISTURE FOODS:– These are foods which can be kept for sometimes before going bad. Their water content is low. Examples of such foods are root vegetables and tubers.
  3. NON- P-ERISHABLE FOODS OR LOW MOISTURE FOODS:– These are foods which can be kept for a reasonably long period without getting spoilt due to their low water content. Examples are nuts, dried legumes and cereals.

EVALUATION:    1. Define food preservation

  1. Give reasons for the preservation of food
  2. Outline four causes of food spoilage
  3. State and explain the classes of food according to the moisture content

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively