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Running head: FINAL INQUIRY PAPER 1
“How Does Smell Affect Our Environment?”
Stephen Greiner
Ivy Tech Community College
“How Does Smell Affect Our Environment?” 2
How Does Smell Affect Our Environment?
The following experiments were performed to satisfy our curiosity on how smell plays a
role in our interpretation of the environment around us. We focused on how it affects our taste
perception and our memory as humans. In our first round, we were looking to answer the
question, How does smell affect taste? We noticed that when we are congested, our sense of taste
is constricted. We claimed that if the tester had their nose plugged, some flavors would not be
identified.
Materials: (These are best prepared in a kitchen environment)
1. Access to tap water
2. Pencil and paper to record the Observations
3. Create a questionnaire
4. Flat clean surface
5. 90 Dixie cups
6. 10 Plastic Spoons
7. 10 Testers (People)
8. Curtains (if preparing in presence of your testers - in our case, umbrellas)
9. Trays
10. Fork
11. Blender/Food processor
12. Red Food Coloring
13. (3) Swimmers nose plugs (with head strap)
14. Master Chart to log all observations and data (See below)
Food Materials:
“How Does Smell Affect Our Environment?” 3
1. Cinnamon/Sugar syrup
2. Salt water
3. Mild Salsa
4. Lime
5. Peas
6. 20 Mint hard candies
7. Peanuts
8. White onion
9. Water
Procedure:
1. Puree your food samples in the following manner:
a. Cinnamon/Sugar syrup: Bring 2 cups water to a boil. Add 2 cups sugar, stirring
until dissolved. Add 2 Tbsp. cinnamon, stirring until dissolved. Allow to cool
completely. Add 2 drops of food coloring and stir until well mixed.
b. Salt water: Mix 11Tbsp. water and 2 Tbsp. table salt. Add 4 drops of red food
coloring and stir until well mixed.
c. Salsa: Puree 1 cup mild salsa with 3 Tbsp. water. Add green food coloring (since
this item was already red in color).
d. Lime: Peel 10 key limes. Puree 5 key limes and squeeze 5 key limes together.
Add 4 drops of red food coloring. Stir until well mixed.
e. Peas: Puree 1 cup of peas with 4 Tbsp. water. Add 4 drops of red food coloring.
Stir until well mixed.
“How Does Smell Affect Our Environment?” 4
f. Mint hard candies: Puree 20 mint hard candies with 7 Tbsp. water. Add 4 drops of
red food coloring. Stir until well mixed.
g. Peanuts: Puree 6 Tbsp. of classic roasted peanuts (unsalted) with 10 Tbsp. of
water. Add 4 drops of red food coloring. Stir until well mixed.
h. Onion: Puree 1 peeled white onion with 2 Tbsp. of water. Add 4 drops of red food
coloring. Stir until well mixed.
2. Pour 1 Tbsp. of the 8 different blended foods into 8 different Dixie cups. In the 9th Dixie
cup, provide drinking water for tester to sip in between samples.
3. Label the Dixie cups 1-9. Make sure to record what number corresponds with each food
on your Master Chart.
4. Before tester begins the experiment, have he/she place a nose plug on so that he/she
cannot smell anything.
5. With the nose plug on, have the tester taste each food and record the flavor that they
taste.
6. Be sure to have the tester rinse their mouth with water between each food.
7. Repeat steps 5 and 6 without the nose plug.
8. Repeat steps 1-8 with 10 tester/people.
9. Ensure that testers have filled out their profile Questionnaire that corresponds with their
recordings.
“How Does Smell Affect Our Environment?” 5
Round 1 Data-With Nose Plug: (Shaded boxes have been eliminated from results due to
unfamiliarity of the foods).
Tester 1-01 1-02 1-03 1-04 1-05 1-06 1-07 1-08 1-09 1-10
#1 Cinna-mon Sugar
Cinna-mon
Cinna-mon
Cinna-mon
Choco-late
X Cinna-mon
X Jello Cinna-mon
Cinna-mon
#2 Salt Water
Salt Salt Salt Bitter Salt X Salt Salt Salt Salty
#3 Mild Salsa
TacoSauce
X X Celery X X X X X Salsa
#4 Fresh Limes
Lemon X Lime Lemon Bitter X X Lemon Ginger sour
#5 Peas
X X X Avo-cado X X X X Peas Vege-table
#6 Mint Candy
Pepper-mint
Mint Pepper-mint
Straw-berry
Pepper-mint
Pepper-mint
Minty X X Pepper-mint
#7Peanut
X X Nuts Milk yogurt
X Peanutbutter
Gritty Horseradish
X Nuts
#8Onions
Onion Onion Onion Banana Onion X X Onion Onion Pico de gallo
Round 1 Data- Without Nose Plug: (Shaded boxes have been eliminated from results due to unfamiliarity of the foods).Tester 1-01 1-02 1-03 1-04 1-05 1-06 1-07 1-08 1-09 1-10
#1 Cinna-mon Sugar
Cinna-mon
Cinna-mon
Cinna-mon
Cinna-mon
Cinna-mon
Cinna-mon
X Cinna-mon
Cinna-mon
Cinna-mon
#2 Salt Water
Salt Salt Salt Salt Salty X X SaltWater
Salt Salty
#3 Mild Salsa
TacoSauce
Salsa Tomato Tomato Salsa Guacamole
X Salsa Salsa Peppers
#4 Fresh Limes
Lemon OrangePeel
Lime Lemon Lime X X Lime Juice
Vinegar Grape-fruit
#5 Peas
X Peas Peas Beans Peas X X X Peas Peas
#6 Mint Candy
Pepper-mint
Pepper-mint
Pepper-mint
Pepper-mint
Pepper-mint
Pepper-mint
Pepper-mint
X Pepper-mint
Pepper-mint
#7Peanut
Peanuts Peanuts Nuts Peanuts Peanuts Peanuts X Peanut Peanuts Peanuts
#8Onions
Onion Onion Onion X Onion X X Onion Onion Pico de gallo
“How Does Smell Affect Our Environment?” 6
Based on our observations and data, certain flavors were difficult for testers to identify
and certain flavors were almost always detected when the tester had their nose plugged.
Cinnamon sugar, mint, onion, salt water, and limes (some identified lemon) were detected by
almost every tester for example. The flavors that were difficult to identify were salsa, perhaps
because it has multiple ingredients, peanuts, and peas. We observed that the peanuts and peas
were not overly aromatic foods. Our claim that some flavors would not be identified with nose
plugs on was supported.
Once the nose plug was removed, we could see a notable increase of accuracy in our
testers. They almost all identified the correct flavor once more aroma was allowed into the nasal
cavity. Some testers even corrected their initial claim for sample 4 from lemon to lime, and
testers would originally stated “nuts” for sample 7 correctly identified “peanuts” without the
nose plug.
To understand our results, we needed to first build or refresh our schema of the human
mouth and nasal anatomy. Beginning research immediately started to reiterate the same idea: The
digestive and respiratory systems work intimately together (Hendrickson, 2013). The Society for
Neuroscience explains that although taste and smell are different senses, they are also engaged
together (Taste and Smell, 2012). In diagrams showing the mouth and nose, we can see that there
are open cavities between the back of the mouth into the nasal area. Tastants (chemicals in food)
are evaluated by the tongue, and odorants (volatile scented chemicals) are evaluated by the
receptors in the nose (Taste and Smell, 2012).
This evaluation of the stimuli that come into either the nose or the mouth of humans is a
very important concept in our research. Chemoreception is when an organism transduces
(transforms external stimuli into cellular response) signals from chemoreceptor to the brain
“How Does Smell Affect Our Environment?” 7
(Chemoreception: Biochemistry, 2015). This is different from organism to organism, and there
are many different chemoreceptors found within the organism (Chemoreception: Biochemistry).
For the purposes of our experiment, we want to focus on the chemoreceptors located in the
tongue and in the nose. In vertebrates, the sensory of taste is perceived either through gustation
(oral) or through olfaction (nasal) (Henshaw, 2012).
The first of these systems to understand would be our tongue, since many humans believe
most of what they taste will occur here. The sense of taste on the tongue is honed for survival
(Barinaga, 2000). Detecting sweetness can mean the food has a high caloric value, and detecting
bitterness can mean it may be poisonous (Barinaga). This sensation of tasting and deciphering
chemicals on the tongue is called gustation (Henshaw, 2012). Aside from gustation, the tongue
has receptors that are responsible for detecting other sensations, like temperature and texture
(Henshaw). So, what is happening on the tongue that allows it to detect these flavors?
Taste receptors are located primarily on the tongue, but also extend back into the upper
part of the esophagus (Chemoreception: Biochemistry, 2015). There are approximately 10,000
taste buds located in this area, including the inner surface of our cheeks (Marieb, Elaine; Hoehn,
Katja, 2010). Visible to the naked eye are the mushroom shaped papillae on the tongues surface,
giving the human tongue its slightly
abrasive texture (Marieb, Hoehn). Within
each of these thousands of papillae, there
are around 50-100 taste receptors, known
in layman’s terms as the taste buds, and
they replace themselves every 7-10 days (Marieb, Hoehn). Located on these taste receptors
(buds) are taste pores, and projecting from these pores are the microvilli (taste hairs) (Shier,
“How Does Smell Affect Our Environment?” 8
David; Butler, Jackie; Lewis, Ricki, 2007). These taste hairs are the sensitive part of the receptor
cell, and once stimulated send a nerve impulse through nerve fibers that travel to the brain (Shier,
David; Butler, Jackie; Lewis, Ricki). For most stimuli to be interpreted in vertebrates, it needs to
be water soluble (Chemoreception: Biochemistry, 2015), and within the mouth, saliva dissolves
the chemical to allow it to bind to specific microvilli receptors for interpretation (Shier, David;
Butler, Jackie; Lewis, Ricki, 2007).
After the brain receives the impulse, one of five sensations is interpreted: sweet, bitter,
sour, salty, and umami (Shier, David; Butler, Jackie; Lewis, Ricki). Sweet taste is educed from
chemicals (mainly carbohydrates) such as sugars, alcohols, some amino acids, saccharin, and
some lead salts (Marieb, Elaine; Hoehn, Katja, 2010). Sour taste is produced by the detection of
acids, and specifically their hydrogen ion in solution. Salt taste is educed from the detection of
metal ions (inorganic salts) or sodium chloride. Bitter taste is educed by alkaloids such as
caffeine, morphine, nicotine, and quinine. Aspirins and other non-alkaloid substances can also
elicit a bitter taste. Umami taste is educed from the detection of the amino acids glutamate and
aspartate (responsible for the beef taste of steak and the flavor of aging cheese) and was recently
discovered by the Japanese (Marieb, Elaine; Hoehn, Katja, 2010).
A single taste cell has receptors for only one taste quality, and many substances produce
a mixture of basic taste sensations (Marieb, Elaine; Hoehn, Katja, 2010). Certain quality
reception happens at different areas of the tongue. In the back of the tongue we can detect
bitterness from substances, at the tip we can detect sweetness, throughout the middle of the
tongue we can detect umami, and sour and salty are detecting along the sides (Marieb, Elaine;
Hoehn, Katja).
“How Does Smell Affect Our Environment?” 9
These facts satisfy the data we found on our testers being able to correctly identify certain
tastes when not fully utilizing their sense of smell, such as the acid from the lime juice, and the
sodium chloride from the table salt mixed with water. Why then did removing the nose plugs
heighten the sense of taste, or allow for more accurate identification of flavor?
That is where the second system of taste sensory comes in- smell. It just so happens that
taste is 80 percent smell (Marieb, Elaine; Hoehn, Katja, 2010). Of the 25,000 genes in our human
genome, more than 1 percent of these genes are dedicated to our sense of smell, and our noses
can smell and encode over 10,000 different molecules (Henshaw, 2012).
The chemoreceptors responsible for our sense of smell are located in the olfactory
epithelium, and this system is called olfaction (Kimball, 2015). Odorant molecules come in
through the nose and dissolve in a mucus layer at the roof of the nasal cavity. This mucus layer
houses the cilia, which are receptors. Once the binding occurs, it activates a G-Protein. This G-
Protein activates an enzyme called adenylyl cyclase, which catalyzes a nucleotide ATP to the
second messenger, cyclic AMP, and this opens up sodium channels for a facilitated diffusion of
Na+. If the depolarization reaches threshold, then it creates an action potential. This is conducted
back to the brain via the olfactory nerve, and the brain codes the nerve impulse as an “odor”
(Kimball, 2015). Long story short, olfaction starts by breathing in airborne molecules and
binding them to olfactory receptors, then these specialized olfactory receptors send the underside
of the brain (temporal lobe) signals through the Olfactory Bulb, and the brain decides what smell
or flavor they are (Shier, David; Butler, Jackie; Lewis, Ricki, 2007).
The Olfactory system is considered one of the oldest in the brain, and is essential in
animal survival. Humans and other animals use olfaction to detect predators, identify food
sources (and whether or not they are safe to eat), and find mates. Smell, even by such noble
“How Does Smell Affect Our Environment?” 10
philosophers as Plato, was regarded as a lesser sense to that of sight or touch. In humans, it could
very well be that our upright body positioning has required us to rely more on that of eyesight,
whereas dogs and other four legged animals need the help of smell to sense dangers they cannot
see as quickly (Henshaw, 2012). Either way, whether noticing subconsciously or consciously,
our noses are deciphering thousands upon thousands of chemicals through olfaction.
With these facts about olfaction, we can conclude from our experiment that once the nose
plugs were removed, it allowed for a greater interpretation of flavors because it engaged more
specialized receptors in the nose. After witnessing these results, the question arose, How would
smelling one item and tasting a differing item affect the flavor? We decided to have our testers
smell an aromatic, competing smell to that of which they would taste. We claimed that this
would affect their ability to identify the flavor of the food.
Materials:1. Access to tap water
2. Pencil and paper to record the Observations
3. Profile Questionnaire
4. Flat, clean surface/table
5. 90 Dixie cups
6. 10 Plastic Spoons
7. 10 Testers (People)
8. Curtains (If preparing in presence of your testers – we used umbrellas)
9. Trays (to transport the samples)
10. Fork
11. Red Food Coloring
12. 9 Small plastic Tupperware (about 4 oz each) containers with lids
“How Does Smell Affect Our Environment?” 11
13. Measuring spoons
Food Materials:
1. (2) 32oz Containers Plain Yogurt
2. Strawberries- pureed
3. Lemon juice
4. Orange juice
5. Banana- pureed
Scented Materials:
1. Scope mouthwash- Mint flavored
2. Black pepper
3. Balsamic Vinegar
4. Crushed red pepper flakes
5. Sriracha sauce
6. Apple Cider Vinegar
7. Lemon Juice
8. Strawberry Puree
9. Coffee grounds
Procedure:
1. Label 8 Dixie cups and 8 Tupperware containers with numbers 1-8.
2. Place 1 Tbsp. plain yogurt in each Dixie cup.
3. Mix 1 drop of red food coloring in each yogurt cup and stir until well mixed.
4. In yogurt cup #2, mix ¼ Tbsp. pureed strawberry. Stir until well mixed.
5. In yogurt cup #4, mix ½ Tbsp. orange juice. Stir until well mixed.
“How Does Smell Affect Our Environment?” 12
6. In yogurt cup #6, mix 1 Tbsp. pureed banana. Stir until well mixed.
7. In yogurt cup #8, mix 1 drop of lemon juice. Stir until well mixed.
8. In the numbered Tupperware containers place the appropriate scent:
#1- 1 Tbsp. Apple cider vinegar
#2- 1 Tbsp. Scope mouthwash
#3- 1 Tbsp. Black pepper
#4- 1 Tbsp. Balsamic Vinegar
#5- 1 Tbsp. Crushed red pepper flakes
#6- 1 Tbsp. Strawberry puree
#7- 1 Tbsp. Sriracha sauce
#8- 1 Tbsp. Lemon juice
9. Place the lids on top of containers and poke holes 3 holes in the top to allow for
smelling to escape.
10. Place 1 Tbsp. coffee in the leftover container. Poke holes in the top to allow for
smelling what is inside.
11. Place the 8 yogurt cups and 8 scent containers in front of the tester.
12. Starting with #1, have the tester smell the scent for 10 seconds, then have the tester
smell the scent while tasting yogurt cup #1.
13. Have the tester record the flavor of yogurt they taste.
14. Have the tester smell the coffee between each sample.
15. Have the tester repeat steps 12, 13, and 14 until all samples have been smelled, tasted,
and recorded.
16. Repeat the entire procedure with 10 testers.
“How Does Smell Affect Our Environment?” 13
Data:
Based on our observations and data, we could not confidently conclude that our findings
were accurate. We believe that our base, plain yogurt, was too easily discernable due to its sour
nature. We also believed that the lids of the containers stifled our scents. Even though you could
smell each one, we believe for the influence to have taken place on taste, it needed to be a
stronger aroma. You can see, however, some interesting findings and relationships.
Almost all of our testers accurately identified the banana-flavored yogurt, even when
smelling strawberry. When smelling black pepper, many testers tried to identify flavors of
Yogurt Flavor Scent Tester:
2-01Tester:
2-02Tester:
2-03Tester:
2-04Tester:
2-05 Tester: 2-06 Tester:2-07
Tester:2-08
Plain Apple Cider Vinegar
Plain
Plain X PlainRuined Cottage Cheese
X X X
Straw-berry
Scope Mouth
washStrawberry Strawberry Blueberry X Strawberry X Strawberry Peach
Plain Black Pepper Plain Lemon Banana X Cottage
Cheese Strawberry X Plain
OrangeJuice
Balsamic Vinegar Berry Lemon Key Lime Peach Kiwi/
Strawberry Mango Peach Lime
Plain Crushed Red Pepper Plain Plain Strawberr
y/Banana Plain Cottage Cheese X Sour Plain
Banana Strawberry Banana Banana X Banana Banana Banana Banana Banana
Plain Sriracha Sauce Plain Plain Sriracha Strawberry Cottage
Cheese X Sour Cheese Plain
Lemon Lemon plain Plain Lemon Plain Cottage Cheese X Sour
Cheese Lemon
“How Does Smell Affect Our Environment?” 14
lemon, strawberry and even banana. So, our claim was somewhat supported. We do not feel the
evidence was overwhelming enough to fully support our claim, since only one scent had an
impact on flavor perception (that of the black pepper).
This particular experiment made me think of how the smell of wine impacts its taste.
What components of wine elicit a response from the brain telling you that flavors are present
although not actually added to the wine (like vanilla, boysenberry, fig, and stone fruit)? We
began to ask questions about how your brain can tell you the flavor is something other than what
it is, such as chemically engineered flavoring or chemical reactions producing different aromas,
such as the alcohol in wine.
It was during the height of this experiment that I attended a wine tutorial with Sommelier
Joseph Davey. We were taught the basic flavors in wine, such as acidic, sweet, tannic, and bitter,
and instructed on the four S’s: Swirl, Sip, Swish, and Spit. By swirling the wine in the glass, it
causes the wine to aerate and for molecules to become airborne, so that you can smell the aroma
with more intensity. This aroma is often referred to as the ‘bouquet’ of the wine. Once we sipped
the wine, he asked up to swallow immediately and reflect on what flavors we perceived in the
wine. After sharing our flavor profiles, we were asked to sip and then slurp the wine, allowing air
intake to aerate within our mouths before swallowing. By doing so, flavors became more intense
and new flavors were present. He defined these volatile airborne aromas as esters.
Esters are a chemical compound derived from carboxylic acids (most commonly) and are
responsible for the fragrance and flavor of fruits and flowers (Esters: Chemical Compound,
2015). Esters are also found in essential oils, pheromones, animal fats, and vegetable fats. Esters
naturally found in fruits and flowers are a natural advantage in attracting potential pollinators and
seed dispersion (Esters, 2015).
“How Does Smell Affect Our Environment?” 15
Carboxylic acids are capricious liquids of low molecular weight, and are colorless and
slightly soluble in water. The formula for a carboxylic acid ester is RCOOR’ and are created by
the reaction of carboxylic acids and alcohols when present with hydrochloric acid or sulfuric
acid. (Esters: Chemical Compound, 2015). Another way to describe the ester of a carboxylic acid
is that the carboxylic acid contains the –COOH group, and in the ester this group’s hydrogen is
replaced by a hydrocarbon (such as an alkyl group – methyl or ethyl, or a benzene ring –phenyl)
(Clark, 2004). The ester responsible for the smell of banana is isopentyl acetate, the ester
responsible for the smell of pineapples is ethyl butyrate, and for wintergreen is methyl salicylate
(Esters: Chemical Compound, 2015). The reverse of esterification is called hydrolysis, and this is
how soap is formed (the salt of a fatty acid) (Carboxylic Acids and Esters, 2013).
Further research became incredibly difficult for a novice chemist like me to fully
understand, so I will only be referring the carboxylic acid esters, like the ones produced in
flowers and fruits.
The esters present in wine are the result of the wines natural ethynol being oxidized in the
air to become ethanoic acid, commonly called acetic acid (from the Latin word acetum, meaning
sour wine) (Carboxylic Acids and Esters, 2013). Now we can see how swirling or swishing the
wine in the glass and in our mouths helps to promote the chemical reaction of ethynol to ethanoic
acid, producing the esters. Depending on the vinification of the wine, and the grape variety used,
presents different smelling molecules. White wines usually produce flavors of herbs, grass,
minerals, tropical fruits and white flowers. Red wine varietals produce flavors reminiscent of
earth, dark fruits, tobacco, leather, and berries. Man made influences such as aging can impart
different flavors to the wine as well, such as oak aged wine having vanillin flavors (vanilla).
“How Does Smell Affect Our Environment?” 16
The perfume ‘industry’ has been harvesting natural esters for thousands of years, and in
the recent decades has been able to commercially reproduce esters to cheaply produce smells
naturally found in nature without having to grow or harvest them.
Now that we had a better understanding of how smell affecting foods and beverages, we
were curious about how it affecting humans in a more social manner and how smell was so
strongly related to our memory. We wanted to know, How do people associate smell with color?
This was a simple way of tapping into the schema of our testers, by using color as the medium of
their memories. We claimed that testers would associate (relate the aroma) to colors and
memories similarly, even if they had a different cultural background.
Materials:
14. Access to tap water
15. Drinking Water
16. Pencil and paper to record the observations
17. Profile Questionnaire
18. Flat clean surface table
19. 10 small Tupperware containers with lids
20. 10 Testers (People)
21. Curtains (if preparing experiment in presence of your testers)
22. Color Wheel – 26 colors
23. Trays
24. Fork
Scents:
1. Chambeli perfume
“How Does Smell Affect Our Environment?” 17
2. Moss
3. Cumin Seeds
4. Cardamom
5. Amber incense
6. Patchouli leaves scent
7. Pumpkin scented wax
8. Dragon’s Blood incense
9. Blueberry Cheesecake scented wax
10. Caramel scented wax
11. Coffee
Procedure:
1. Prepare all materials by first labeling 10 small Tupperware containers with lids from
numbers 1-10.
2. Place the 10 different scents in 10 different containers individually.
a. #1- Spray Chambeli on a paper towel 10 times and place the paper towel in the
container.
b. #2- Fill container with moss.
c. #3- 2 Tbsp. of Cumin Seeds.
d. #4- 2 Tbsp of Cardamom
e. #5- Amber oil, soaked into paper towel or cotton.
f. #6- Broken pieces of Patchouli Leaf scented incense
g. #7- Broken pieces of Pumpkin scented wax.
h. #8- Broken pieces of Dragon’s Blood scented incense.
“How Does Smell Affect Our Environment?” 18
i. #9- Broken pieces of Blueberry Cheesecake scented wax.
j. #10- Broken pieces of Caramel scented wax.
3. Place the lids on the containers.
4. Poke 4 holes in the top of the lid with a fork to allow for smelling what is inside.
5. Set the 10 containers in front of the tester in a tray on a clean, flat surface table.
6. Place the Color Wheel on the clean flat surface table.
7. Have the tester smell each fragrance and write down the color choosing from the color
wheel they think of, and why.
(It is important to instruct testers that if the color is not necessarily present on wheel, to
choose the closest representative. If it is absolutely not present, like an ‘electric color,’
have them write down that it is ‘not represented.’
8. Repeat the procedure with 10 testers (people).
9. Record your data onto a Master Chart.
“How Does Smell Affect Our Environment?” 19
Data:
This experiment had the most participants, and included a better ratio of male to female
participants, as well as a better ratio of American raised and non-American raised individuals
(mostly from Central America). We found some really interesting similarities. Interestingly,
testers who associated a smell as ‘clean’ almost always used blue or white, regardless of cultural
“How Does Smell Affect Our Environment?” 20
heritage. Testers who identified with ‘earth’ almost always used green. This was truly interesting
because earth is a brown or natural color, and plants that grow there are green. So most people
stated ‘earthy’ as their reasoning but identified with the color of foliage, regardless of cultural
heritage. Testers who identified a smell as ‘floral’ almost always used pink or white- and a few
used lavender- but no one associated floral with red. Testers who identified with ‘spice’ used
either red for fresh peppers or brown for dried peppers. Testers who stated it made them think of
‘candy’ almost always used bright pink.
An interesting study that arose during research was that of an international research team
comparing the relationship of smell to color from multiple cultural groups. They wanted to know
if smell to color was hardwired (neurological) or influenced by culture, just like our group did.
They found that participants, regardless of cultural heritage, associated fruity smells with pink or
red, and musty smells with orange and brown. Soaps were found to be pastel colors, and plastics
were neutral, dark colors (Olson, 2014).
Not all studies done to relate smell to color based on culture have agreed with these
findings. There is data that shows Australians associate almonds with the color blue, while
Canadians chose red (Chang, 2014). The studies find that within a culture, there are strong
similarities, and there are even striking similarities among separate culture groups, like we found
in our study (Chang). However, there are just enough differences to negate the idea that we are
genetically engineered to perceive smells the same, regardless of culture.
So why does smell generate such a response from the memory? I personally find that I
will smell something and have very specific imagery, even from when I was a very young child,
come to mind. It would be my hypothesis that it is a survival skill to remember smells so that you
can avoid or revisit them with more confidence. If something you smelled and ate made you sick,
“How Does Smell Affect Our Environment?” 21
the smell may trigger you to avoid it later. I have drunk too much of a particular type of liquor
before, and the smell of it to this day makes me feel nauseous.
When you look deeper into the connection of olfaction to the brain, you can see that the
temporal lobe that houses the olfactory epithelium also houses the amygdala and the
hippocampus, and they are all directly linked. The hippocampus is strongly associated with
memory, while the amygdala puts emphasis on the value, such as positive or negative. The
amygdala is responsible for eliciting a behavioral response (Shier, David; Butler, Jackie; Lewis,
Ricki, 2007). The Limbic System, or Association, which contains the hippocampus, amygdala
and other functioning parts, is the brain area that puts an emotional impact on chemical stimuli
(Marieb, Elaine; Hoehn, Katja, 2010). We saw Professor Wylie’s response to the pureed, colored
food in our experiment as negative, because she associated it with Pepto Bismol, which she
detests.
The limbic structures closely relate to the olfactory cortex and have a role in olfactory
sensation. Amygdala functions in food choice and emotional intonation of food intake (like when
you get dumped and you drown yourself in ice cream). The most active part of the brain while
we sleep is the limbic system, tying together emotion and memory during rapid eye movement to
form the content of dreams, derived from unconscious primal emotions and conscious cognitive
thoughts and perceptions (Rajmohan, V.; Mohandas, E. (2007).
So, how does the limbic system relate to color, as in our experiment? Color has an
incredible impact on our primitive brains. It can affect our moods, likes and dislikes, and can
stimulate danger signs or comforting signs (Graff, 2014). When we were conducting our
experiment, we were discussing that the color red is highly used in food production, especially
fast food, because it makes people hungrier. And you really don’t see a lot of blue used in foods.
“How Does Smell Affect Our Environment?” 22
In fact, no tester ever associated a food item in our experiment with blue, not even the blueberry
cheesecake. Color affects our moods based on how they behave in nature. For instance, we
associate fire with red and orange. Orange has been proven in studies to increase oxygen supply
to the brain, produce an energizing effect, and stimulate brain activity, whereas blue is the color
of stability and calm, like a calm, storm-less blue sky. Hockey and football teams who changed
their jerseys from black to white incurred less aggression penalties, research shows (Van
Edwards, 2012). Colors used as associations were directly pulled from testers memories of the
smell and how it looked in nature, almost always from a flower, a food, or some other tangible
item that they had already seen and stored in their memory. No one used emotions to describe a
smell. No smells made them think of ‘happiness, therefore yellow.’
Another sub-concept that we came across in our research of olfaction was that of
pheromones. A pheromone is a chemical that is emitted from an animal that affects the behavior
of another member of the same species. It is a form of silent communication between social
animals, primarily insects, and generally is used as a sex signal, aggressive signal, trailing signal,
alarm signal, disarming signal, and recognition signal (Cotton, 2012). Although studies are still
controversial in human research, there have been many studies that show reactions in sexual
behaviors between humans in particular situations. In a research study between men and women,
researching collected the tears of women after they watched an emotional movie, and the men
that smelled the tears had a decrease in testosterone and arousal- perhaps from the chemical
signal that sex was off the table. Another study in 2005 shows that gay men preferred the scent in
sweat from other gay men, while heterosexual men favored the scent of sweat from women
(Everts, 2012). From all of the research we have found about olfaction and behavior, smelling a
chemical signal to elicit a behavior is the fastest response.
“How Does Smell Affect Our Environment?” 23
In conclusion, because olfaction sends nerve impulses into the emotional parts of our
brains, they trigger memories and emotional responses based on how we stored our experience
with these stimuli before, or how we are experiencing them for the first time. Olfaction and
Gustation both send their signals to the Thalamus, which is involved in sensory and motor signal
relay. The sense of smell ends here for both olfaction and gustation, whereas other sensory
triggers are sent to relevant cortical areas (Mandal, 2015).
Taste is affected highly by smell because, as we found out, taste is almost all smell.
When the noses of testers were plugged, aromas could still enter the upper nasal cavity and
promote a reaction through the olfaction receptors. Together with impulses sent from taste buds,
testers could make accurate identifications of foods.
It was interesting to find during research that there has been many serious studies done
similarly to what we had originally created, and how similar the results were. This was a very
insightful project to how important and relative smell is to almost all facets of life, whether it be
to taste, memory, emotion, or mood, and whether it be conscious or subconscious.
If I were to continue my research and testing, I would want to learn more about
synesthesia, the disorder that 1 in 27 people have in some capacity in which you put a different
sensory value on something. For instance, you can taste music, or numbers are colors. Also, it
would be interesting to learn more about smell and how it affects mood, and what is proven to
calm your mood, since I struggle so much with anxiety.
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