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  • Writer's pictureSara

How do certain ingredients impact the chemical processes in the formation of a cake?

Hi, everyone!

This post consists of a few experiments I performed, their findings, and the science behind it all.

I hope you enjoy it!



Project Question: How do certain ingredients impact the chemical process in the formation of a cake?

In this project, we will be using a basic sponge cake recipe using flour, sugar, eggs, baking powder, and a liquid (to wet the batter). We will be exploring how each ingredient impacts the formation of the cake and the various chemical processes the ingredients undergo to form a cake.

The recipe we will be following will be the same for each experiment with the elimination of one or two ingredient(s) at a time.

Image depicting a sponge cake

Control Experiment

In this experiment, we will be using flour, sugar, eggs, baking powder, and vanilla essence. We will be using this experiment as a comparison for experiments 1 to 5. Here, all the variable factors have been kept constant.

Aim: To use as a standard of comparison for the other experiments.

Method: Mixing all the wet ingredients, and then adding in the flour. After mixing all the ingredients, we bake the batter in the oven.

Image depicting the batter of the control experiment

Image depicting the final control experiment

Note: For all the experiments, a cupcake mould has been used instead of a cake mould. The cupcakes remained in the oven till a toothpick (in the control experiment cupcake) came out clean.


Gluten Formation (Flour)


  • What is gluten?

Gluten is a common term for proteins (large molecules that are composed of amino acids) present in all kinds of wheat and other grain species such as barley, rye, and triticale. It is an important functional protein component in wheat-based doughs.

Image depicting certain baked products that contain gluten

  • Formation of gluten

The formation of gluten occurs when two naturally occurring classes of water-insoluble proteins in wheat flour (known as glutenin and gliadin) are hydrated with H2O and mixed. Through this process, the formation of gluten bonds occurs along with the formation of a tough rubber-like substance (that provides strength as well as structure). The mechanical shear causes the formation of gluten bonds. It becomes a ‘viscoelastic matrix’ that holds the starch granules in the flour.

An important fact to note, through the above information, is that raw flour alone cannot contain gluten (as compared to batter or dough). Thus, gluten does not exist in nature. It is only formed when water is mixed with wheat flour.

  • What do the naturally occurring proteins (glutenin and gliadin) do?

Glutenin’s main function is to provide elasticity (ability to recover after the dough is stretched) and strength (a measure of the amount of force needed to stretch a dough), while the main function of gliadin is to provide extensibility.

When adequate water is added to previously dry flour, the two proteins emerge from their earlier so-called frozen form and can move around.

  • Chemical Formation of Gluten

Image depicting a flowchart of the chemical formation of gluten

The specific chemical process of gluten formation has to do with hydration. As water is mixed in with the flour, hydrated proteins are brought together and start to interact with each other – sticking together through the formation of chemical bonds (cross-links). In the case of gluten, different types of bonds form between proteins with disulphide bonds stronger than, say, hydrogen bonds.

  • How does gluten help in the formation of a cake?

With the aforementioned information, we now have a fair idea as to how gluten works. Now the question that arises is: how do we connect gluten to baking?

Almost all traditional baked goods use a form of flour – the most common being wheat flour (that is largely composed of starch, protein, and gluten). Thus, gluten is an important component in baking.

Functions of gluten include:

a. Maintaining the volume, appearance, and texture of a baked good. When subjected to heat, gluten proteins solidify and a half-rigid structure forms that provide the classic texture of wheat products.

b. Helping in the rising of dough by trapping bubbles during fermentation.

c. Providing structure and trapping gases (since the protein can form elastic films in the dough). This assists in the leavening of baked goods.

Also, as mentioned earlier, when water is added to flour, the gluten bonds that form (due to the proteins in the dough forming linkages) provide structure and elasticity to dough.

Image depicting the fact that there is a certain structure to the dough (due to gluten formation)

In baking, for chewy bread, high amounts of gluten are required, whereas, for a more tender cake, less gluten formation is favoured. The formation of gluten can be controlled by which flour you are using (whether it has more protein or less protein).

Experiment #1

Aim: To find out how the absence of gluten impacts a cake.

Method: For this experiment, we will follow the same recipe as the control experiment except that the flour will be replaced with almond flour.

Hypothesis: As per the research above, gluten-free flour will produce a drier cake with lesser volume. Lack of visco-elasticity in the flours without gluten usually creates a more pasty and sticky batter, with low H2O binding properties and low gas retention.

Picture of gluten-free cupcake batter

Conclusion and Analysis: After seeing the baked cupcakes, we find our hypothesis to be true since the cupcake turns out to be drier than the control experiment.


Maillard Reaction (Sugar and Eggs)

  • What is the Maillard reaction: Maillard reaction in cakes

Commonly known as a browning reaction, the Maillard reaction (first observed in 1913 by French chemist Louis-Camille Maillard) is responsible for the browning as well as the aroma of foods. The Maillard reaction is what causes cakes to brown. Other common foods that undergo this reaction are cookies, steaks, biscuits, and bread.

In simple words, the Maillard reaction is a reaction between simple sugars (reducing sugars) and amino acids (that are the building blocks of proteins). Monosaccharides, disaccharides, and amino acids are all biological compounds that participate in the Maillard reaction.

For the reaction to occur, it is essential for the food being cooked to contain proteins and sugars in the right proportion.

When eggs are used for glazing, they act as a protein source in the reaction. This is seen in croissants when they turn brown due to the egg glaze.

Browning of croissants due to the Maillard reaction

A guide to the Maillard reaction

  • Steps in the Maillard Reaction

There are three primary steps in the Maillard reaction:

1. “Initial condensation of a carbohydrate carbonyl group with an amine, followed by a series of reactions leading to the formation of the Amadori product.

2. Rearrangement, dehydration, decomposition, and/or reaction of Amadori intermediates to form furfural compounds, reductones and degradation products.

3. The reaction of Maillard intermediary products to form heterocyclic flavour compounds and red/brown to black coloured, melanoidin pigments of high molecular weight.”

Maillard reactions cause transformations that include a generation of melanoidins from light yellow to dark brown, while simultaneously generating flavour and aroma. An unfavourable effect of the Maillard reaction is that under extreme conditions, mutagenic or potential carcinogenic (cancer-causing) compounds (e.g. acrylamide) can form.

Image depicting the formula of acrylamide

Image depicting the Maillard reaction in a simple equation form

  • Conditions required for the Maillard reaction

The numerous conditions that favour the occurrence of the Maillard reaction are as follows:

1. Adequate heat

A temperature higher than 140°C is required for the Maillard reaction to take place. This is why we see the Maillard reaction occurring in cakes, steak, etc. These products are subjected to high heat in the oven or a cast iron pan.

Many foods such as sweet rice contain both sugar and protein but they do not have a brown appearance or the aroma that is caused by the Maillard reaction. Similarly, boiling of steak does not cause the Maillard reaction – the boiling point of water is only 100°C.

Image depicting an oven

2. Adequate moisture

Too much moisture causes a wet surface, which may hinder the food from reaching high temperatures faster. As mentioned before, the Maillard reaction requires a high temperature.

This is one reason why salt is commonly used in baking – it draws out the moisture, creating ideal conditions for the Maillard reaction to occur.

3. Sugar and protein content

Products that are rich in reducing sugars can enhance the Maillard reaction.

4. Presence of free water in the system

More water activity enhances the sugar’s molecular mobility as well as amino acid solutes in the dough.

5. pH

Alkaline conditions are suitable for the occurrence of the Maillard reaction. The optimal browning takes place at a pH of 6-8.

6. Fermentation

The yeast activity, the amount of yeast, etc. may be detrimental to the extent of the reaction.


Role of Eggs as a Binding Agent

  • What is a binding agent?

Binding agents are ingredients that help a mixture in maintaining its shape or binding. Binding agents may add texture to the goods.

  • Eggs as binding agents

Eggs play a crucial role in baking by creating structure and maintaining stability in a batter. Additionally, they add moisture to cakes and can act as glue or a glaze (page 5).

If eggs are mixed with sugar, they can trap and hold air. The combination of the two also adds moisture and flavour to a recipe.

Image explaining what an egg as a binding agent means

  • Other roles of eggs

Eggs can provide liquidity to the batter. Beaten egg, when added to a mixture, stops fat-coated air bubbles from collapsing when heated. Egg proteins form a layer around each air bubble. With the rising temperature of the cake, in the heat, the layer coagulates – forming a rigid wall around each bubble, preventing it from bursting and ruining the texture of the cake.

Image depicting the functions of eggs in cooking

Experiment #2

Aim: To find out how the absence of sugar impacts a cake.

Method: For this experiment, we will follow the same recipe as the control experiment except that the sugar will be omitted.

Hypothesis: As per the research above, the absence of will lead to a less brown top as the Maillard reaction will not properly occur.

Picture of sugar-free cupcake batter

Conclusion and Analysis: After seeing the baked cupcakes, we find our hypothesis to be true since the cupcake turns out to look whiter than the control experiment. It has not browned as much as the control cupcake.

Experiment #3

Aim: To find out how the absence of eggs impacts a cake.

Method: For this experiment, we will follow the same recipe as the control experiment except that the eggs will be omitted.

Hypothesis: As per the research above, eggs act as a binding agent (as well as help in wetting the batter). The ingredients will not be bound properly – they will be looser and drier.

Picture of egg-free cupcake batter

Conclusion and Analysis: After seeing the baked cupcakes, we find our hypothesis to be true since the cupcake turns out to be flakier than the control experiment. It is not bound properly and loose flour is present. The Maillard reaction has also not properly occurred – there is negligible browning on the cupcake.

Experiment #4

Aim: To find out how the absence of sugar and eggs impacts a cake.

Method: For this experiment, we will follow the same recipe as the control experiment except that the sugar and eggs will be omitted.

Hypothesis: As per the research above, the Maillard reaction should not occur at all since there will be no sugar or protein.

Picture of sugar-free and egg-free cupcake batter

Conclusion and Analysis: After seeing the baked cupcakes, we find our hypothesis to be true since the cupcake turns out to be white. There is no occurrence of the Maillard reaction (seen by no browning) since eggs and sugar were not present in the batter.


Leavening Agents (Baking Powder)

  • What is a leavening agent?

A substance that causes the expansion of the dough and the batter by releasing gases within the mixtures to produce baked goods with porous structures is known as a leavening agent.

Image depicting leavening agents in baking

  • Chemical leavening agents

Chemical leavening agents are made with compounds or mixtures that release gases in reaction with each other, moisture, or heat, usually used in cooking that requires a quicker fermentation effect (such as cakes).

Chemical leavening agents are usually made up of a bicarbonate salt and an acid. This reaction produces a chemical salt.

The most common chemical leavening agents are:

a. Baking Powder

Baking powder is a fine white powder. When in the presence of liquid and heat, it releases carbon dioxide. The powder has a built-in acid that activates it.

Image depicting baking powder

b. Baking Soda (NaHCO3)

Baking soda, also known as sodium bicarbonate, is a fine white powder that comprises a mixture of alkaline salts. Baking soda is manufactured by adding carbon dioxide to water (that contains NaCl and NH3). Once the NaHCO3 settles at the bottom, it undergoes filtration, washing in cold water, and drying. Then, it is ground to a fine powder.

Baking soda requires an acidic ingredient for activation (e.g. lemon juice).

Image depicting baking soda

  • More about baking powder

As mentioned earlier, baking powder is a chemical leavening agent – usually a mixture of baking soda, dry acid (cream of tartar or sodium aluminium sulphate), and cornstarch.

Cornstarch absorbs moisture, preventing a reaction until the addition of a liquid. Baking soda neutralizes acids, helps with leavening, and adds tenderness.

When liquid is added to a baking recipe, baking powder reacts to form bubbles of carbon dioxide gas.

The reaction that occurs between sodium bicarbonate (NaHCO3) and cream of tartar (KHC4H4O6) is:

NaHCO3 + KHC4H4O6 → KNaC4H4O6 + H2O + CO2

Sodium bicarbonate and sodium aluminium sulphate (NaAl(SO4)2) also react in a similar manner:

3NaHCO3 + NaAl(SO4)2 → Al(OH)3 + 2Na2SO4 + 3CO2

  • How does the reaction of baking powder work in a cake?

When we add a water-based ingredient to a cake, the chemical reaction produces carbon dioxide bubbles. This is the reason we don’t leave the batter in a refrigerator overnight – it may spoil the recipe.

Before putting the cake in the oven, about 15% of CO2 gas is released in the cold stage. The other 85% of the gas is released in the oven starting at approximately 40°C. Though some leavening power is lost in the cold stage, there is still adequate ‘gassing power’ in the remaining portion.

When the baking powder is activated through moisture and heat, the gas works its way into the many cells created by the mixing or creaming of the batter and starts to expand them. This process comes to a halt when the starch gelatinizes and the cells become rigid. This starts at about 60°C and is mostly finished at around 75°C. After this point, some gas may still be created, but it simply escapes through the porous structure of the product.

Baking powder also enlarges and