Flour is the powder obtained when whole wheat (or any other cereal) is ground (milled).
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Milling is the process of crushing and grinding grains into powder by passing them through a machine. All cereal flours could either be of low extraction rate or high extraction rate. The most commonly used cereal for flour is wheat.
- Low Extraction rate flours: They are produced from cereals after all the outer layers have been removed. The remaining central endosperm is ground into flour, which is very white and low in nutritive content.
- High Extraction rate flours: These are produced from partially milled cereals that still retain some of the outer layers. They are not very white like the low extraction flours but are better in nutritive value.
COMPOSITION OF FLOUR
- Starch is the main component of any flour.
- Gluten: This is the protein in flour. It is elastic and impermeable. It is gluten that makes wheat flour the most common flour in bread making.
- Water: It contains up to 16% water.
- Sugar: The quantity of sugar is very small, but it plays a very important role in fermentation.
- Define the term ‘flour’.
- Differentiate between high extraction and low extraction flours.
TYPES OF FLOUR
- Whole wheat flour: This contains all the natural constituents of wheat in an unaltered proportion. It is rich and natural but cannot be kept for long.
- Instant blending flour (Agglomerated flour): This has the texture of uniform sized particles. It does not need to be sifted since it flows freely and disperses easily in cold water.
- All- purpose flour: It is used for all kinds of cooking since the protein content is average.
- Soft wheat flour: This is very soft, smooth and powder-like without granules. It is low in protein and is used for cakes, cookies, pastries and crackers.
- Hard wheat flour: This contains high protein. It is heavier in texture and good for bread making.
- Cake flour: It is made from soft wheat. It contains low protein and retains its shape when pressed lightly.
- Self-raising flour: This contains salt, baking powder and other ingredients, so can rise on its own without raising agents. It is good for plain cakes and scones.
- Pastry flour: It is soft and smooth. It is used for making pastries, cookies, etc.
- Composite flour: This is a mixture of two or more types of flour in a specific ratio or proportion.
These are items which make flour mixtures rise and double in size. The commonly used raising agents are:
- Air: Air is a natural raising agent. Air is incorporated into flour mixture during creaming or beating which gets expanded when heat is applied. This principle works for dishes like sponge cake, pan cake, omelette, etc.
- Baking powder: This is composed of a mixture of an acid, tartaric acid or cream of tartar and an alkali called bicarbonate of soda. Rice flour is added to keep baking powder dry instead of damp and lumpy. Baking powder is used in cakes, pastries, etc.
- Yeast: Yeasts are living cells which become active and grow when placed in a warm damp place and mixed with little sugar. Yeast is used in bread and doughnut making.
- Palm wine: This contains yeasts and is used in commercial production of bread in bakeries.
- Cream of tartar and bicarbonate of soda: When used separately, they act more quickly than baking powder.
- Steam: Steam aids the expansion of flour products such as cream puffs.
- Mention and explain three types of flour.
- What are raising agents?
These refer to products obtained from flour and other ingredients. Flour serves as the main ingredient. Flour mixtures are grouped according to the ingredients and the raising agents used. They are as follows:
- a) Pastry: This is a mixture of flour, fat, salt and liquid. It is used to prepare meat pie, sausage rolls, cream puff, etc. Baking powder is the raising agent used.
- b) Dough: This is a mixture with very little butter. Yeast is the raising agent used. Such mixture is used for bread dough, doughnuts, dinner rolls, etc.
- c) Batter: This is a flour mixture with enough liquid, salt, egg and flour to make it a bit watery with a pouring consistency. Air is the raising agent used and this mixture is used for pancakes, Swiss rolls, spring rolls, etc. It is also used for coating of foods to be fried.
- d) Cakes: These are rich flour mixtures with equal quantity of butter and sugar. Eggs are added to make it rich. Baking powder is the raising agent used. This mixture is used for all types of cakes, buns, chin-chin, etc.
GENERAL EVALUATION QUESTIONS
- List and explain five types of flour.
- Define the term ‘raising agents’ and give examples.
- What are flour mixtures?
- What is milling as applied to cereals?
- Differentiate between low extraction and high extraction rate flours.
- The following are flour products except ____. A. barbeque B. sausage roll C. biscuits
- The mixture of two or more types of flour is called ____. A. mixing flour B. composite flour C. ratio flour D. general flour
- ____ is the raising agent used in bread and doughnut. A. Air B. Steam Yeast D. Baking powder
- What type of flour can be used for all kinds of flour products? A. Pastry flour Self-raising flour C. Instant blending flour D. All-purpose flour
- The following are ingredients for making cake except ____. A. eggs B. fat C. palm wine
- Explain the following: a) Low extraction rate flour b) High extraction rate flour
- List four flour mixture.