LESSON 4.6
"The Importance of Baking Process"
The baking process is responsible for major weight loss in the dough/batter, mainly moisture (8–12%) and volatile organic compounds, especially in pan bread and buns. Chemically leavened products may have higher bake losses. For labeling purposes, the loss in weight during baking is taken into account during dough dividing or batter depositing.
The main parameters involved in the baking process include: time, temperature, humidity, air flow (convection systems) and heat flux. These process variables are a function of the size, unit weight, formulation, water absorption, type and target characteristics of the finished product. Baking times may range from 2–60 minutes, depending on the type of oven and heating pattern.
The Introduction
Structure builder – Also called toughener.
Examples: flour, eggs, cocoa powder, cornstarch.
• The proteins and starches in flour, eggs, and cocoa powder are the actual structure builders.
– Holds the volume and shape of baked goods in place.
– Too much structure results in tough, hard-baked goods.
3. Moistener – Thins out batters and doughs.
Examples:
• Water (moisture) and ingredients that contain water, including milk, eggs, cream, and syrups.
• Oil and melted fat.
2. Tenderizer – Interferes with the formation of structure.
Examples: sugars and syrups, fats and oils, leavening agents
– Softens baked goods, making them easier to bite into.
– Too much tenderizing leads to crumbling or collapse.
4. Drier – Opposite of moistener.
– An ingredient that absorbs moisteners.
Examples: flour, cornstarch, dry milk solids, cocoa powder.
The Baking Process
Stage I: Mixing
The mixing method is important
– Example: muffins mixed using muffin method compared with the creaming method
• Ingredient temperature is important
– Example: pie pastry dough mixed with cold vs. warm ingredients
(As batters and doughs are mixed:)
• Ingredients are distributed evenly throughout.
• Air bubbles are mixed in and reduced in size.
– Lightens batter/dough.
– Provides for proper leavening and crumb formation.
• Large solid particles are worn down, layer by layer, into smaller ones.
– Allows them to dissolve or to hydrate faster.
• Fats/oils break into small chunks or droplets.
Stage II: Baking
During baking: – Heat is slowly conducted from the outside in.
– Heat transforms batter/dough from a foam that traps air bubbles to a porous sponge that does not.
• Term sponge is used whether product has a springy, spongy texture or not.
Crumb, or grain, of baked goods consists of air cells surrounded by porous cell walls.
Baking involves at least eleven events :
(1) Fats Melt (7)Gases Evaporate
(2)Gases Form and Expand. (8)Caramelization and Maillard Browning
(3)Microorganisms Die (9)Enzymes are Inactivated
(4)Sugar Dissolves (10) Changes Occur to Nutrients
(5)Egg and Gluten Proteins Coagulate. (11)Pectin Breaks Down
(6)Starches Gelatinize.
Stage III: Cooling
Carryover cooking continues until baked goods reach room temperature.
• Changes occur during cooling and continue during storage.
– Changes occur even when baked good is properly wrapped.
• Many changes result in the firming of baked goods as they cool.
– Best to cool products to 100ºF (38ºC) or below before slicing
Eight main changes:
1. Gases contract; weak structure collapses.
• Example: soufflés
2. Fats resolidify.
• Decrease in greasiness, but the product could become hard and waxy.
3. Sugars recrystallize.
• Provides crunchy crust in low-moisture products.
4. Starch molecules bond and solidify.
• Called retrogradation; a major cause of staling.
5. Proteins bond and solidify.
• Contributes to staling.
6. Moisture is redistributed within crumb.
7. Moisture moves from moist crumb to dry crust.
• Crust loses crispness; can become tough and rubbery.
8. Flavors evaporate or become trapped by starches.
• Brief reheating in oven recovers some lost flavor.
Baking of yeast-leavened bakery products (dough-based systems)
Coming out of the final proofer, the bread dough is well aerated with a typical internal temperature close to that of the proof box, around 35°C (95°F). As the dough pieces enter the oven, their surface temperature begins to increase and heat transfers slowly towards the core of the product. The oven temperature can be set, according to the type of product being processed, at any point between 200–300°C (390–570°F).
Baking of chemically-leavened products
In this case, the three stages of baking (oven spring, setting of structure and crust formation/coloration) can undergo changes in response to differences in type and amount of ingredients in the formulation. Chemical reactions and physical transitions during heat processing may be affected by:
High content of water in the system (hydration of flour and other dry ingredients) which creates a liquid or fluid batter.
Flour to sugar ratio (high ratio cakes contain more sugar than flour). This has a big impact on starch gelatinization, protein coagulation, and water evaporation. Low flour content also requires higher levels of structure-building ingredients such as whole eggs.
Rich formulations (higher content of soluble solids such as sugars, fat, etc.) that shift the system towards an aerated oil-in-water emulsion known as batter.
Absence of yeast but presence of leavening acids and bases that can modify leavening reactions and these require specific conditions of temperature and available water.
Modification of pH due to the presence of chemical leaveners which can affect final color of crust/crumb and taste of finished product.
THE BAKING PROCESS:
The changes to a dough or batter as it bakes are basically the same in all baked products, from breads to cookies and cakes. You should know what these changes are so you can learn how to control them.
The Stages in the Baking Process
1. Formation and expansion of gases
The gases primarily responsible for leavening baked goods are carbon dioxide, which is released by the action of yeast and by baking powder and baking soda; air, which is incorporated into dough and batters during mixing; and steam, which is formed during baking.
Some gases — such as carbon dioxide in proofed bread dough and air in sponge cake batters — are already present in the dough. As they are heated, the gases expand and leaven the product. Some gases are not formed until heat is applied. Yeast and baking powder form gases rapidly when first placed in the oven. Steam is also formed as the moisture of the dough is heated.
2. Trapping of the gases in air cells
As the gases are formed and expand, they are trapped in a stretchable network formed by the proteins in the dough.
These proteins are primarily gluten and sometimes egg protein. Without gluten or egg protein, most of the gases would escape, and the product would be poorly leavened. Bread without enough gluten is heavy.
3. Gelatinization of starches
The starches absorb moisture, expand, and become firmer. This contributes to structure. Gelatinization of starches
begins at about 140°F (60°C).
4. Coagulation of proteins
Like all proteins, gluten and egg proteins coagulate or solidify when they reach high enough temperatures. This process gives most of the structure to baked goods. Coagulation begins when the temperature of the dough reaches about 165°F (74°C). Correct baking temperature is important.
If the temperature is too high, coagulation starts too soon, before the expansion of gases reaches its peak. The resulting product has poor volume or a split crust. If the temperature is too low, the proteins do not coagulate soon enough, and the product may collapse.
5. Evaporation of some of the water
This takes place throughout the baking process. If a baked product of a specific weight is required, allowance must be made for moisture loss when scaling the dough. For example, to get a 1-lb loaf of baked bread, it is necessary to scale about 18 oz dough.
6. Melting of shortenings
Different shortenings melt and release trapped gases at different temperatures, so the proper shortening should be selected for each product.
7. Crust formation and browning
A crust is formed as water evaporates from the surface and leaves it dry. Browning occurs when sugars caramelize and starches and sugars undergo certain chemical changes caused by heat. This contributes to flavor. Milk, sugar, and egg increase browning.
Video Materials
Learning Activity 14
Click the google form below and answer.
References
Learning Materials:
[1]https://bakerpedia.com/processes/baking/?fbclid=IwAR0RXzqnGhvYaqEMvwSJAtVnF4hszwHwMoUfQsZAes5ynyjtUOacs6rgnnc
[3]https://www.pps.net/cms/lib/OR01913224/Centricity/Domain/3997/Ch_3_Overview_of_Baking_Process.pdf
Video Materials:
[1]https://www.youtube.com/watch?v=e8tymUqV2-4
[2]https://youtube.com/watch?v=piCbao_xfgY