Chemical Reactions:
Cooking, the Maillard reaction, pyrolysis, marshmallows,
and second chances
Directions: Chemical reactions are a part of everyday life, especially
cooking. Read the articles and pay attention to the two chemical
reactions discussed – the Maillard reaction and pyrolysis – and the
types of molecules that react in different foods while they cook.
What is the Maillard reaction?
Maillard, pronunciation = my-YAR (French)
Amino acids = building blocks of proteins
Protein = important molecules found in foods like meats and eggs
The Maillard reaction is a chemical
reaction that produces flavor and
color changes during cooking. It is
named after French chemist, LouisCamille Maillard.
The Maillard reaction gives foods that contain protein – steak, seafood,
chicken, eggs, and even bread – a brown color as they cook. The
reaction happens when amino acids in proteins and simple sugars
chemically react at temperatures above 285° F (140° C).
The Maillard reaction also produces pleasant aromas – such as the
smell of bread baking. However, it is most important for the flavors that
it creates. The reaction can create hundreds of new flavor compounds
in foods that are baked, grilled, or roasted. This is why grilled chicken is
more flavorful than boiled chicken.
What is Pyrolysis?
From ancient Greek:
Pyro = fire
Lysis = separating
Pyrolysis, pronunciation = pie-rahl-isis
Controlled Pyrolysis:
Sugars begin caramelizing (browning) at
approximately 340 degrees F (170° C). One
example that comes to mind is a perfectly
golden-brown marshmallow.
Caramelization produces caramel, a product
used to color soft drinks and other food
products. This is an example of controlled
pyrolysis.
Uncontrolled Pyrolysis:
When cooking temperatures get too hot,
uncontrolled pyrolysis causes food to
become charred or blackened. Charred
compounds make food bitter. This is why
burned popcorn (or marshmallows) is
unpopular! The black-brown crust found
on barbecue grills, ovens, and stoves is a
product of uncontrolled pyrolysis.
Review questions (photosynthesis & cellular
respiration):
1. What is a chemical reaction?
2. How are photosynthesis and cellular respiration examples of
chemical reactions?
Reading questions (Maillards and pyrolysis):
3. During the Maillard reaction what two types of molecules
chemically react to create a browning effect and produce flavors?
4. During pyrolysis, what type of molecule causes caramelization?
5. Is toasting a modern marshmallow (ingredients listed below) an
example of the Maillard reaction or pyrolysis? Why?
6. Traditional marshmallow recipes include eggs. Would toasting a
traditional marshmallow be an example of the Maillard reaction,
pyrolysis, or both? Why?
7. Can you reverse Maillards reaction or pyrolysis? Why or why not?
8. If you burn a marshmallow, how does it give you a second chance
to fix your mistake?
Modern
marshmallow
ingredients: