Lesson Notes By Weeks and Term - Senior Secondary 2

Raising agents

Get it on Google Play
Get it on the Apple App Store
  1. Home
  2. Lesson Notes By Weeks and Term
  3. Senior Secondary 2
  4. Raising agents

Term: 2nd Term

Week: 6

Class: Senior Secondary School 2

Age: 16 years

Duration: 40 minutes of 2 periods each

Date:       

Subject:      Food and nutrition

Topic:-       Raising agents

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

  1. State th properties and composition of raising agents

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 flour mixtures

Students pay attention

STEP 2

EXPLANATION

She states and explains the properties of raising agents

Students pay attention and participates

STEP 3

DEMONSTRATION

She states the composition of raising agents

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

Raising agents

Raising or leaving agents are substances that produce gas in flour mixtures which cause them to rise and become lighter, bigger and softer in texture and porous after cooking. The use of a raising agent is based on the principle that hot air rises and expands.

These include:

i.) Air (omelettes, sponge cakes)

  • Air: when air is incorporated into flour mixture and put into the oven to bake, the trapped air expands in volume and therefore leavens the product. Air beaten into egg white is the principal raising agent of omelette, sponge cakes and angle cakes.

 

ii.) Baking powder (cakes, biscuits)

  • Baking powder: consists of an acid (cream of tartar or tartaric acid) and an alkali (bicarbonate of soda) with the addition of some starchy ingredient such as rice flour which proportion of ingredient is twice the amount of acid to alkali i.e.

4gm cream of tartar

3gm bicarbonate of soda

2gm rice flavour.

 

iii.) Cream of tartar and bicarbonate of soda

 

iv.) Yeast ( bread, puff-puff)

  • Yeast: the scientific name for yeast is saccharomyces cerevisial. Yeast is made up of a large number of minute’s cells. When kept cool and dry, the cells are inactive, when added to water with a little sugar and gently warmed, the yeast grows rapidly, giving off carbon dioxide which works through the dough making it light. Extreme heat kills yeast and it can have no further activity. Cold retards or hinders its action but does not kill it.

 

v.) Palm wine ( commercial bread)

  • Palm wine: this is a good raising agent for it contains yeast. It is used for commercial bread making and is more economical than yeast. Warmth, sugar and moisture are necessary conditions for its raising action like yeast. Excessive heat, cold and too much sugar retard or stop its growth. Sometimes, for large scale bread making, overripe banana are used to produce a raising agent with the same characteristics as yeast or palm wine. The overripe banana are left to ferment before they are put into use for the purpose. Flour products you can use palm wine as raising agent are bread of different types.

 

vi.) Steam

  • Steam: is an effective raising agent. Steam is the principle raising agent in pop overs and cream puffs. Steam contributes to the expansion of baked products in which other raising agents are used.

EVALUATION:    1. Define raising agents

  1. List and explain the properties and composition of four raising agents

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively