1. The Jolly Rancher Experiment
Illustrating the importance of
Random Design in Experiments

2. Questions to Answer
Why does gum or candy sometimes last longer than other times?
Do the environmental conditions in your mouth effect how long the candy lasts?
What factors in your mouth effect the longevity of gum or candy?

3. What is Known Gum and candy are flavored by sugar
Liquid, like water or saliva, can only dissolve so much sugar = point of saturation
Different drinks have different properties
Sugar levels, pH level, carbonation, etc.
According to the ADA (dentists) the two factors that lead to tooth decay (dissolving enamel) are sugar level and pH (acidity) of foods we eat…

4. What is Known pH (scale of 1-14) is a measure of acidity
Everything has a pH or potential hydrogen
Low pH (1-7) = acidic = sour or tart tasting
High pH (7-14) = alkaline = bitter tasting
Most drinks are 7.0 or lower because we don’t like bitter tastes
Sugar levels vary in drinks
Varies from 0 to 20 grams per serving
So what are some sugar and pH levels of things we consume???

5. What is Known Liquid (8 oz serving) pH level Sugar level Stomach Acid
1.4 (reference)
???
Sunny Delight
2.4 (acidic)
20 g (high)
Cranberry Juice
3.0 (acidic)
8 g (low)
Chocolate Milk
6.8 (non-acid)
26 g (high)
Distilled Water
7.0 (non-acid)
0 g (low)

6. What is Known
Notice, most acidic drinks have at least some sugar to counter the tart acidic taste
What about “7-Up”??
Actually named for being very non-acidic or pH levels “above 7” or “7-Up”
That’s why mom said to drink it when you puke, because it neutralizes the stomach acid
We can’t use it in our experiment because…
Because it is carbonated. The other trial drinks are not carbonated and thus non-carbonated cannot be a constant.

7. Designing The Experiment
Question: Do pH and sugar level of saliva affect the dissolving of hard candy?
Hypothesis: Consuming drinks with a _______ pH and _______ in sugar will dissolve hard candy faster than other drinks.
Independent Variable: Combinations of pH level and sugar
Have the students write down the design of the experiment.

8. Designing the Experiment
Treatments:
1-High pH-High Sugar=Milk
2-Low pH-Low Sugar=Cranberry Juice
3-High pH-Low Sugar=Water
4-Low pH-High Sugar=Sunny Delight
Trials: # of students in class/ 4 treatments
We will tally and analyze all Ag Sci classes data together for more trials
Ex. 28 students in class = 7 trials per class

9. Designing the Experiment
Dependent Variable: Amount of sugar dissolved in grams
Constants:
No talking
Sucking time
No biting
Same amount of liquid
Liquid swished for 10 seconds
Same candy

10. Designing the Experiment
What about the uncontrollable variables?
sucking method, flavor of Jolly Rancher, breakfast foods, teeth brushing, DNA etc.???
That is why Random Design is so important
We cannot control all variables, but having a large number of trials and a randomly designed experiment helps counter these

11. Procedures
Prep 1- Using the Sharpie, write your name on the candy wrapper
Prep 2- Unwrap the candy and set it on the wrapper- DO NOT EAT IT or throw away the wrapper
Prep 3-Weigh your Jolly Rancher with the wrapper and record on your paper
Prep 4-Get your assigned drink based on your playing card suit but don’t drink yet
Jolly Ranchers usually weigh the same within .2 grams. If time is tight, you can omit this step and tell everyone the weight of their candy prio to sucking.

12. Procedures
Step 1- Swish assigned treatment in your mouth but DO NOT swallow
Step 2- Swish liquid for 10 seconds and swallow
Step 3- As a class start sucking on candy at the same time
Step 4- Suck Jolly Rancher without talking for 4 minutes

13. Procedures
Step 5- Remove candies and allow them to dry on wrapper for 24 hours to remove saliva
Step 6- Weigh candies with treatment groups to determine sugar dissolved
This can be reported as a total for the treatment group, or as an average amount
Should be consistent with other data
Step 7- Organize and analyze data as a class, then combine classes to increase trials