Bakery Lab Test- Chocolate Cake

OBJECTIVES           :

To compare the final product of two different method and ingredient and investigate the factor contributed with the final product’s appearance.

A)   BASIC FORMULA FOR SPECIAL CHOCOLATE CAKE (TREATMENT 1)

NO	Ingredients	Metric
1	Cocoa powder	1 cup
2	Water	1 cup
3	Coarse sugar	½ cup
4	Butter	250 g
5	Self rising flour	250 g
6	Eggs	6 eggs
7	Castor sugar	360 g
8	Vanilla essence	1 teaspoon

METHODS

1.     The chocolate paste was made by heating 1 cup of cocoa powder, 1 cup of water and ½ cup of coarse sugar.

2.     The butter and sugar were mixed by electrical mixer until become light and fluffy.

3.     The vanilla essence and egg was added one at a time which alternate with the flour (it was folded and not mixed).

4.     The cocoa paste and  the mixture were mixed together.

5.     The mixture was divided into 2 tins and baked in a moderate oven 175^oC.

B)    BASIC FORMULA FOR CHOCOLATE CAKE TREATMENT 2

NO	Ingredients	Metric
1	Self rising flour	½ Cup
2	Superfine Sugar	½ Cup
3	Cocoa	2 level tablespoon
4	Salt	A pinch
5	Melted Butter	¼ cup
6	Milk	½ cup
7	Egg	1 unit
8	Vanilla	A little

METHODS

1.     The oven was preheated, and the pan was greased and floured.

2.     All ingredients were placed into a mixing bowl in the above order.

3.     Then they were beaten well for 2 minutes

4.     After that, the batter was poured into a prepared pan.

5.     In preheated oven, the batter was baked at 350^oC for 40 minute until the test cake was done using the toothpick.

RESULTS

NOTES: 

LEFT:  T1

RIGHT: T2

EVALUATIONS

	CRUMB	CRUST
TREATMENT 1	Fine texture, smooth, and even pores	Thin crust
TREATMENT 2	Has tunnel at the centre, dark brown. Soggy	Thick, Tough and harden

  

DISCUSSIONS

Chocolate cake from first recipe gives great texture of crumb and crust of the cake. In contrast, the second cake give a worse texture of the crumb and crust. Both cakes have distinct different in their attributes. This differences can be evaluated from their ingredients itself. Table below shows the baker’s percentage of both cakes. The first cake is denoted as T1, while the second one is denoted by T2.

NO	Ingredients	T1	T2
1	Cocoa powder	86%	28%
2	Water	96%	-
3	Coarse sugar	39.2%	-
4	Butter	100%	112%
5	Self rising flour	100%	100%
6	Eggs	144%	120%
7	Castor sugar	144%	200%
8	Vanilla essence	1 teaspoon	A little
9	Salt	-	4%
10	Milk	-	240%

T1’s recipes shows contained higher percentage of cocoa powder (86%) and eggs (144%). While T2’s recipes give higher concentration of liquid (240%), butter (112%), sugar (200%) and self rising flour. The different amount of liquid contributes to distinct attributes of final product.

Regardless of the richness or ratio of tenderizers and tougheners, all ingredients must be balanced according to their function in a cake batter. For example the structural or toughening ingredients such as eggs and flour should be equalized with tenderizing ingredients like fat and sugar. Likewise the liquid ingredients should be balanced with the dry ingredients. The formation of the starch-protein matrix is important for the support and strength of the cake crumb. When these two ingredients are varied it affects the matrix. The varying sugar concentration will affect the extent of starch gelatinization and denaturation of protein. The addition of increasing levels of sugar in a recipe inhibits these phenomena and thus the matrix is weaker. The weakening of the matrix may make a fluffier, lighter product or make a product that will collapse depending on the ratio used.

Traditional recipes call for the weight of the sugar never to exceed 100% of the weight of flour. However, commercial recipes containing higher levels of sugar (30% or more) are becoming popular. These improve the quality of the cake by increasing the volume, tenderness and softness of the cake. This is possible commercially because of additives currently available. The weight of fat is generally less than 50% of the amount of sugar. The closer to the 50% weight of fat, the better the quality of the cake due to an improvement in tenderness, flavor, grain, texture and moisture. The correct amount of liquid in relation to other ingredients in the cake is essential for a high quality product. The weight of the liquid (liquid: milk, eggs) should be approximately equal to the weight of flour. When the liquid or sugar is too high in relation to the flour, the resultant batter is very fluid and the finished cake will lack structure.

During the heating of the batter several basic phenomena occur. The leavening action of both carbon dioxide and steam, gelatinization of the starch granule and coagulation or denaturation of the egg and flour proteins are three primary phenomenon. The fat melts and moves along the convection currents which arise due to the heat action. As the fat melts, it releases the air it trapped during mixing to the flour-water medium. Enlargement of these air spaces occur in the batter during the latter part of baking. The gas is given off by this batter system as it is heated along with some expansion of the batter.  The gas cells are surrounded by a thin layer of batter which expand with the cells when they are heated. Expansion of the cells increases the pressure within them and also increases the movement of the batter. These bubbles rupture when a maximum pressure inside is reached and the film surrounding the cell resists further expansion. The coagulation of the egg and flour protein and gelatinization of starch causes the resistance to expansion of the cells. at this point the batter becomes set.

 

DISCUSSIONS

Baking involve the gradual transfer of heat from the surface of cakes to their center. As heat travels through, it transforms batter and doughs into baked goods with a firm, dry crust and a softer center. The soft center of baked good consist of air cells surrounded by porous cell walls. These cell walls consist of a network of egg and gluten proteins embedded with starch granules.

In order for a cake to rise, it must have a leavening agent to make the batter increase in volume. Most of the cakes use carbon dioxide, which is released from the baking soda or baking powder in the recipe. This carbon dioxide needs a place to go, so that’s where the sugar comes in. The first step in making a pound cake is to take a fat, such as butter or shortening, or a combination of the two, and beat it with an electric mixer. This incorporates air bubbles. Then, sugar is sprinkled slowly into the butter. As the sharp sugar crystals cut into the butter, tiny pockets are formed and fill with air as the mixer blades pull more butter over the top of the hole to close it. This makes the butter double in volume and become creamy in texture, which is why this procedure is called “creaming.”

If the crystals of the store brand sugar are smaller than the old favorite, or the edges of the crystals aren’t as sharp, they won’t cut into the butter as deeply. This makes a smaller hole, so less air can be pulled through. Then, the eggs are usually added, which adds more volume and allows the mixture to hold even more air. The dry ingredients, including the baking powder, are then added, usually alternating with liquid. When the baking soda or powder comes into contact with liquid, carbon dioxide is released. As the batter heats up, bubbles form and the batter rises. As the carbon dioxide breaks down, the moisture in the cake forms steam, which fills the air pockets our sugar made. Eventually, the steam evaporates, but by this time the protein in the flour has had enough time to set, thus making the cake hold its shape.

 Huda Sakinah