Popcorn
A Consumer Chemistry Project by Kelsey
The Chemistry of Popcorn
 Popcorn is a delicious treat, enjoyed by individuals
worldwide. My research project investigates the
chemistry behind one of my favourite foods, popcorn!
 This project provides an in depth look at the composition
of popcorn, the factors that allow it to pop, as well as
the many molecules and chemicals that make up the
aroma and smell. In addition to this, popcorn brands are
compared and health issues that may arise during
manufacturing are explored.
Popcorn Composition
 Popcorn is composed of three main layers. The first, and
outer most layer, is known as the pericarp. This is an
outside shelling that provides strength and durability to
the kernel. It can come in many colours including
yellow, white, black, and even red.
 Underneath the pericarp, exists the endosperm. Water
and starch are both trapped within this layer. It also
contains smaller parts protein, fat, and minerals.
 The final layer is the germ (also known as the embryo).
This is the makeup of the seed that eventually pops.
 Finally, is the tip cap, the part joining the kernel, which
would have attached to the cob.
What Makes Popcorn Pop!
 H2O is trapped in the endosperm. As the kernel heats
up, H2O begins to change state from liquid to gas.
Steam begins to expand, thus building up pressure in
the pericarp. The endosperm grows increasingly inflated
until the pericarp gives way to the kernel. The popcorn
explodes as it flips inside out, steam escapes, and the
white fluffy starch is exposed. At this moment, your
popcorn has just “popped”!
Popcorn Aroma
 Popcorn odour comes from molecules released into the
air as popcorn is heated.
 Recent spectroscopic studies have determined over fifty
chemical compounds that contribute to the aroma and
flavour of popcorn. Some names may sound familiar
after studying organic chemistry, while others are
completely new. Several examples include…
Aroma Chemical Compounds
2-methyl propanol
Hexanoic acid
Pentanol
Furfuryl alcohol
Flavour
 In some popcorn, such as the microwavable kind,
flavourings are added which contribute to the aroma.
 Ex.) Butter-flavoured popcorn can include the chemical
compounds 2,3-butanedione or 2,3-pentanedione
Health Hazards
 Popcorn is generally thought to be a healthy option
when choosing a snack. It is a good source of dietary
fiber and low in calories, when eaten plain.
 Unfortunately, if your go to snack is microwavable
popcorn, you may be missing out on the many benefits
of eating popcorn and instead, putting yourself in harms
way. Recent studies conducted by Chemical Research in
Toxicology have identified the chemical compound 2,3butanedione, better known as Diacetyl (DA), in artificial
butter flavouring. A high quantity of DA in the body may
result in a dangerous build up of plaque in the brain.
This leaves the body susceptible to Alzheimer’s disease,
toxic effects on nerve cells, and penetration of the
blood-brain barrier by unwanted substances.
Health Hazards 2.0
 The chemical compounds added for flavour pose a
serious respiratory threat for workers in factories that
manufacture these compounds. The condition is known
as “popcorn lung”, with the medical name bronchiolitis
obliterans. As the name suggests, the condition
obstructs the airway and makes breathing difficult for
the victim. Popcorn lung can be crippling, as the effects
are irreversible in the small airways. If serious enough,
lung transplant may need to be considered as a
treatment option.
Popcorn Brands & Popability
 The list of different microwavable popcorn manufacturers is
nearly endless. Many different companies have created their
own version of the snack, so the question to be asked is “how
do they differ?”.
 The quality of a bag of popcorn is largely based on the
“popability” of the kernels inside. This refers to the ratio of
popped kernels vs. unpopped kernels. The secret to good
popability lies in the outer shell of the kernel and it’s chemical
composition. Kernels that are more likely to pop tend to have
a strong outer hull with a highly ordered crystalline structure.
Another factor playing into the likeliness of popping is the
water composition in the endosperm. Scientists have
determined that the ideal moisture content is approximately
14% of the kernel’s weight.
Popcorn Brands & Popability 2.0
 Researcher and food chemist, Bruce Hamaker,
investigated the matter of unpopped popcorn kernels.
Through his studies, he discovered some of the best
popcorn brands had a failure rate of only 4%, while the
worst brands failed to pop 47% of the kernels.
 A popular brand, Orville Redenbacher claims to have a
popcorn popability in which 98% of their kernels pop.
Research Log
 March 3rd  1 hour
 March 15th  1 hour
 April 7th  1 hour
 May
4th
 2 hours
 May 5th  1 hour
 May 18th  0.5 hours
 May 25th  1 hour
Total Time Spent on Research:
7.5 hours
Sources
• Reid, D. J. (2015). Popcorn. In World Book Encyclopedia. (Vol. P, pp.659).
Chicago, IL: a Scott Fetzer Company
• Wilkinson, B. (n.d.). The Chemistry of Popcorn. Retrieved April 07,
2017, from http://www.chemistryislife.com/t-3
• Brunning, A. (2017, January 19). What Makes Popcorn Pop? – The
Chemistry of Popcorn. Retrieved April 07, 2017, from
http://www.compoundchem.com/2017/01/19/popcorn/
• Walradt, J.P. (1969). Flavor Chemistry of Popcorn. Retrieved April 07,
2017, from http://www.worldofchemicals.com/228/chemistryarticles/chemistry-of-popcorn-aroma-popping.html
• Anonymous (n.d.). Chemistry of popcorn aroma & popping! - World Of
Chemicals. Retrieved April 07, 2017, from
http://www.worldofchemicals.com/288/chemistry-articles/chemistry-ofpopcorn-aroma-popping.html
• American Chemical Society. (2005, April 15). The Chemistry Of Popcorn: It's
All About 'Pop-Ability' Retrieved May 25, 2017, from
https://www.sciencedaily.com/releases/2005/04/050415112829.htm