No love for Pineapple --- The Jell-O Lab

Linfei Liu
A Block Hon. Bio
02/16/14

No Love For Jolly Pineapple (Enzyme’s effectiveness in Relation to Temperature) 

                                                                                                                        -- The Jell-O Biology Lab

ABSTRACT:
For this lab, we explored the properties of the enzyme, Bromelain, in relation to temperature and how temperature could affect the function of Bromelain; furthermore, we figured out the relationship of Bromelain and Jell-O formation. During this lab, we discovered that temperature could change the shape of Bromelain; thus, temperature could affect the function of enzyme, namely Bromelain in this lab. Also, we found out that Bromelain would become ineffective and unable to break down the collagen of the Jell-O at high temperatures. This discovery confirms our prior knowledge of the characteristics of enzymes that enzymes function properly under certain circumstances, such as optimal pH level and temperature.

INTRODUCTION

QUESTION:
Why does it say on the directions “Do not use fresh or frozen pineapple, use cooked or canned”? What is the difference? Why would it matter? What does Jell-O have in it? What does pineapple have in it that doesn’t mix?

 
BACKGROUND:
Bromelain is a natural enzyme that could be found in the juice, stem, and fruit of the pineapple. The enzyme, Bromelain has been used as a digestive enzyme to aid the internal organs in digestion. Also, it is an anti-inflammatory enzyme as it is used for reducing swelling (inflammation), especially of the nose and sinuses, after surgery or injury. Furthermore, Bromelain supplements are promoted as an alternative remedy for various health problems including joint inflammation and cancer. Bromelain has been used for hundreds of years in folk medicine. As mentioned before, this type of enzyme would affect the formation of Jell-O. Bromelain contains two enzymes that have the ability of breaking down proteins called proteases. Jell-O, a type of gelatin, structures itself by form links between chains of collagen. However, Bromelain could cut these chains of collagen and keep the gelatin from being jelly properly. Fresh pineapple does this as a natural self-defense. Whereas canned pineapple is heated during the canning process. Thus, the enzymes in Bromelain in the pineapple are inactivated as their optimal temperature of functioning is changed to about 158° F. This is the reason why Jell-O needs to be formed by using canned pineapple.

HYPOTHESIS:
If we use canned pineapple, which is already heated, Jell-O will form. Yet, other types of pineapple would not work, such as frozen pineapple and fresh pineapple. 

METHODOLOGY
MATERIALS:
· 6.69g of Jell-O powder
· 39.4mL of hot water
· 39.4mL of cold water
· 2.4g frozen pineapple
· 2.4g canned pineapple
· 2.4g fresh pineapple
· 4 petri plates with covers
· 3 graduated cylinders
· 3 stirring rods
· 1 refrigerator
· 1 hot plate
· 1 beaker

PROCEDURE:
1. Boiling an amount of water greater than 80mL in a beaker on the hot plate.
2. Prepare the variables, such as frozen pineapple, canned pineapple juice, and fresh pineapple juice.
3. Put these variables into their own petri plate and label them
4. Make a control plate (no pineapple presented in the plate)
5. Pour 6.6 g of Jell-O powder into the beaker
6. Add 39.4 mL of boiling water into the beaker, and mix the powder and the water well with the stirring rod.
7. For each plate, evenly distribute 10mL of hot water, 10mL of cold water, 1.65g of Jell-O powder, and 1mL of the pineapple juice (depends on the plate, pour in different type of juice or pour in nothing).
8. Cover all the petri plates and carefully label each one of them.
9. Bring the petri plates to the refrigerator and begin cooling.
10. Allow the Jell-O to settle, come back next day to check the data.

Canned Pineapple---formed Jell-O 

Canned Pineapple

Fresh Pineapple --- nothing 

Frozen Pineapple --- nothing

Control Plate (no pineapple) --- formed Jell-O

RESULTS:

Plates	Set	Liquid	Jell-O formation
Control (No pineapple)	Yes	No	Successful
Jell-O with frozen pineapple	No	Yes	Fail
Jell-O with canned pineapple	Yes; yet, not as firm as the control plate	No	Successful
Jell-O with fresh pineapple	No	Yes	Fail

As shown in the graph, Jell-O is formed in the control plate and the plate with canned pineapple juice, and the plate with frozen pineapple juice and the plate with fresh pineapple would not form Jell-O.

CONCLUSION:
As mentioned in the hypothesis, if we use canned pineapple, which is already heated, Jell-O will form. Yet, other types of pineapple would not be able to make Jell-O become set, such as frozen pineapple and fresh pineapple. In relation to our hypothesis, our final result fails to reject our hypothesis. While the Jell-O containing fresh pineapple/ frozen pineapple did not become set, the canned pineapple formed Jell-O. Our testing result supports our hypothesis. The lab result is successful. Therefore, when Jell-O mixes with the pineapple that still containing Bromelain, Jell-O would not be set properly as Bromelain would break Collagen Bonds. Nevertheless, when Jell-O mixes with heated pineapple (canned pineapple), Jell-O would form properly due to the reformation of the collagen bond’s shapes and active site. Bromelain is inactive in the canned pineapple. During this lab, we also set up a control plate with nothing in it but Jell-O (this is the regular plate), and we kept the amount of hot water, the amount of cold water, the amount of Jell-O powder, and the amount of the juice to be constant. Also, we kept the temperature during the Jell-O- formation period to be the same, since all the plates were placed in the same fridge. Although our final result is successful, there are still some sources of error as well as human error:
1) Inaccurate measurement of the amount of necessities that we need for the lab may cause some errors.
2) False measurement of the amount of product.
3) Need to do more trials to confirm a more accurate result.
4) Could have tested other fruits to check the result.
5) Contamination of different types of pineapples
6) Crossing contamination of Bromelain.
Last but not least, through this lab, we have learned a critical characteristic of enzymes -- the effect of temperature on the function of enzymes. 

CITATION:
American Cancer Society (2001, April 06). Bromelain. Retrieved from http://www.cancer.org/treatment/treatmentsandsideeffects/complementaryandalternativemedicine/herbsvitaminsandminerals/Bromelain
Mr. Kevin Quick, Lecture at The Webb Schools, 2014.
Natural Medicines Comprehensive Database (2013, April 24). Bromelain. Retrieved from http://www.nlm.nih.gov/medlineplus/druginfo/natural/895.html