Taste Preferences

Abstract

This Experiment involves examining taste preferences of coke vs. diet coke.

Taste preferences are subjective and individuals vary in what tastes better.

Taste involves taste buds on the tongue and is affected by many factors local and psychological.  Most people who consume carbonated drinks regularly can notice the difference and will have a particular favourite. Results show that Coke was the preferred beverage with a higher rating in sweetness and a pleasant after taste then diet coke.

Description

Human being have specialised taste receptors located on the tongue and it is seen that some areas of the tongue are more sensitive to taste then others  for example sweet or salty is tasted towards the front of the tongue while bitter is tasted more behind. Perception of taste also appears to be influenced by thermal stimulation of the tongue. In some people, warming the front of the tongue produces a clear sweet sensation, while cooling leads to a salty or sour sensation (Bowen, R2006) There are certain threshold levels for which taste is stimulated and different types of sweet things can have different levels which can explain why sucrose is sweeter then lactose if a similar amount is used.

Examples of some human thresholds(Bowen,2006)
Taste	Substance	Threshold for tasting
Salty	NaCl	0.01 M
Sour	HCl	0.0009 M
Sweet	Sucrose	0.01 M
Bitter	Quinine	0.000008 M
Umami	Glutamate	0.0007 M

Methods

Materials

1 can of Coke, refrigerated for 24 hours or more

1 can of diet coke, refrigerated for 24 hours or more

1 bottle of bottled water (not mineral water), at room temperature

4 cups of equal/identical size and appearance

2 colored markers or crayons (red and blue)

1 survey form

1 tray or plate for presenting the filled cups to your participant

Procedure

1. Twenty-four hours (or more) before conducting your Soda-Challenge put the two cans of soda in the refrigerator.  (Hide them if you must to prevent them from being accidentally consumed by an unknowing, innocent bystander.)
2. Making an effort to not allow the marks show through the bottom of the cups, mark the bottom of one cup with a blue circle.  This cup will later hold the Pepsi sample.  Mark the bottom of a second cup with a red circle.  This second cup will contain the Coke sample.  The remaining 2 cups will contain the bottled water.
3. Print out a copy of the survey form.
4. Set up your drinks (pour 1/4 cup, or 2 oz, of each drink them into the designated cups).  To decide which soda you will present first to your participant, flip a coin (Heads = Pepsi, Tails = Coke).  (Make a note of which beverage you are presenting first.)  Place all 4 cups on a tray in a row (coin-toss winning soda first, water second, other soda, then last water).  Place the try in your chosen research area.

1. Once you have a participant, offer him, or her, the survey form.  Allow him or her a few seconds to complete Section A of the survey form.  Once your participant indicates that he or she is done move on to the taste test.
2. Taste Test:  Inform your participant of the procedures you will follow.
   1. Read:

The following brief study will be completed in two phases.

  First, you will be presented with a carbonated beverage to taste and drink. Please drink the entire contents of the cup.  Once you have consumed this first beverage, rinse your mouth well by drinking a cup of water.  Note, this will likely require you to use a brief swishing action (as you would after brushing your teeth), before swallowing the water.  Upon swallowing the water, complete section B of the survey form.  When you are done notify me and we will move forward with part two of the study. Phase 2 of the study will follow the same steps as Phase 1.  You will be offered 1) a cup containing a carbonated beverage to taste, and 2) a cup of water to clear your Pallet.Once you have consumed the beverage and water you will complete Sections C and D of the survey. Follow the procedures you have read.

Offer the coin-toss winning soda first Offer water to clear the pallet

Allow time for the completion of Section B

Offer beverage 2

Offer water

Allow time for the completion of Section B

Ask him/her to answer the question in

Thank your participant, and then explain, in your own words the purpose of the study.

Results

–Survey 1

-Participant #1: 30 year-old male, drinks about 3 carbonated drinks per day, 14x per week, and 36-40 times per month.  Does have a favourite drink; Pepsi and consumes Pepsi the most frequently.  Says Diet Pepsi is least favourite carbonated drink.

Using the 5-point scale:

Sample 1: Coke
Sweetness: 2
Tartness: 0
Syrupy: 0
Pleasant after taste: 3
Unpleasant after taste: 0

Sample 2: Diet Coke
Sweetness: 1
Tartness: 0
Syrupy: 1
Pleasant after taste: 1
Unpleasant after taste: 0
Preference: First Sample (Coke)

–Survey 2

–Participant #2: 34 year-old female, drinks about 2 carbonated drinks per day, 10x per week, and at least 40 times per month.  Does have a favourite drink; Coke and consumes diet coke the most frequently.  Says Diet Coke is the least favourite carbonated drink.

 Sample 1:  Coke
Sweetness: 3
Tartness: 0
Syrupy: 0
Pleasant after taste: 4
Unpleasant after taste: 0

Sample 2: Diet Coke
Sweetness: 1
Tartness: 0
Syrupy: 0
Pleasant after taste: 2
Unpleasant after taste: 0
Preference: First Sample (Coke)

–Survey 3

-Participant #3: 28 year-old female, drinks about 1 or 0 carbonated drinks per day, 3 times per week or less, and 5 times per month.  Does have a favourite drink; Pepsi and consumes Pepsi the most frequently.  Says Root Bear is least favourite carbonated drink.

Sample 1:  Coke
Sweetness: 2
Tartness: 0
Syrupy: 0
Pleasant after taste: 3
Unpleasant after taste: 0

Sample 2: Diet Coke
Sweetness: 1
Tartness: 0
Syrupy: 0
Pleasant after taste: 4

Unpleasant after taste: 0

Preference: Second Sample (Diet Coke)

Discussion

From the above it shows that coke is rated as more sweet with a better pleasant after taste. Two participants preferred the sweeter coke while one preferred diet coke showing that it is a matter of personal preference rather then which one is sweeter. The basic ingredients are carbonated water, high fructose corn syrup, sugar, colorings, phosphoric acid, caffeine, citric acid, and natural flavors (Wikepedia,2008) The diet version uses an artificial sweetener called sucralose instead of sugar which gives the different taste. Diet Coke or Coca-Cola Light may be sweetened with a blend containing cyclamates, aspartame, and acesulfame potassium,

References

Diet Coke (2008) Wikipedia. Retrieved from the World Wide Web on the 22^nd of June 2008:

http://en.wikipedia.org/wiki/Diet_Coke

Bowen, R (2006) Physiology of Taste Retrieved from the World Wide Web on the 22^nd of June 2008:

http://www.vivo.colostate.edu/hbooks/pathphys/digestion/pregastric/taste.html