The document summarizes several key chemical reactions that occur during the baking of cakes: 1) Leavening agents like baking soda, baking powder, and yeast produce carbon dioxide that causes dough to rise by reacting with acids or feeding on starches. 2) Sugar undergoes the Maillard reaction above 300°F, browning the crust and producing flavors. 3) Eggs act as an emulsifier and binder, trapping air bubbles and holding the cake structure together with proteins like lecithin. 4) Flour proteins bond together when mixed with water to form gluten, giving baked goods their structure.

1. Chemical Reactions
Involved in Baking a Cake
A presentation by Guru Ashish.p

2. Most baking is based on the use of flour, the powder form of grains, nuts
and beans. Wheat flour, the most commonly used type of flour in baking,
is composed largely of starch and protein, with very high levels of a class
of protein known collectively as gluten. When water is added to wheat
flour, the gluten forms a heavy, pliable mass. This expands greatly under
hot temperatures and sets with the desired airy texture.

3. Leavening Agents
Leavening agents such as baking soda, baking powder and yeast give baked dough
its lightness. Baking soda reacts with acids in the dough to make carbon dioxide,
which helps the dough to rise. Baking powder, which is baking soda with an
additional acidic salt, releases carbon dioxide twice during the baking process,
once when it hits water, and again when it reaches a certain temperature in the
oven. Heat helps baking powder produce tiny bubbles of carbon dioxide, which
make a cake light and fluffy. When yeast, a single-celled fungus that feeds on
starch and sugars, is added to dough, it also releases carbon dioxide bubbles,
giving the dough a light, delicate texture.

4. Browning Reactions
Sugar does much more than just sweeten a cake. When the baking
temperature reaches 300 degrees Fahrenheit, sugar undergoes what is
known as a Maillard reaction, a chemical reaction between amino acids,
proteins and reducing sugars. The result is browning, which forms the crust
of many baked goods, such as bread. The Maillard reaction is not the same as
caramelization, but both work together to create appetizing golden-brown
surfaces and an array of flavors. Sugar also provides a direct food source for
yeast, enhancing the yeast's activity.

5. Emulsification and Binding
Eggs in a cake mixture may fulfill one or more of three functions. Beaten egg
white is used, like baking powder, to give the dough a light, fluffy consistency.
This is possible because egg white (albumen) contains lecithin, a protein that
coats the air bubbles created during beating, which stops the cake from
sinking during baking. ILecithin also acts as a binder to hold the cake together.
When egg is used as a glaze, it also acts as a source of protein for the sugar's
Maillard reaction.

6. Protein Bonding
Flour contains two important proteins -- glutenin and gliadin. When water is added to
flour to make dough, it allows these proteins to bond together and from a new protein
called gluten. Kneading the dough intensifies these gluten bonds. After the dough is
place into a heated oven, it begins to rise and grow the gluten network. This network
eventually hardens during the baking process, giving the inside of a loaf of bread or
similar baked good its signature structure.

7. Magic Leaveners
Leavening agents -- such as yeast, baking powder and baking soda -- give baked dough
its pillowy lightness. Baking soda achieves this by reacting with acids in the dough to
produce carbon dioxide gas, which puffs up the dough. Baking powder releases carbon
dioxide twice during the entire baking process -- once when it hits water and once when
it reaches a certain temperature in the oven. When yeast is added to dough, it begins to
feed on starches -- producing sugars, alcohol and carbon dioxide as byproducts. As with
baking powder and baking soda, the carbon dioxide produced by yeast causes the
dough to rise

8. Maillard Reactions
Maillard reactions occur when proteins and sugars are broken down and
rearranged by high temperatures. These sugars and proteins can be derived from
flour by itself, or they can be enhanced with the addition of sugars and eggs. The
reactions produce ring-shaped organic compounds that darken the surface of
baking dough. Maillard reactions also produce toasty and savory aromas and
flavor compounds. These compounds also react among each other, producing
even more complex aromas and flavors.

9. Flavors of Caramelization
Caramelization, which occurs at 356 degrees Fahrenheit, is the last chemical reaction to
occur during the baking process. The reaction occurs when high heat causes sugar
molecules to break down and release water, which turns into steam. Diacetyl, which
gives caramel its butterscotch flavor, is produced during the first stages of
caramelization. Next, esters and lactones, which have a rum-like flavor, are produced.
Finally, the production of furan molecules imparts a nutty flavor, and a molecule called
maltol imparts a toasty flavor.