Fruit enzyme lab

Rahul Salagame

9/15/13

Biology Honors

Fruit Enzyme Lab

ABSTRACT

            This experiment was designed to find out how certain enzymes affect proteins and the various conditions in which enzymatic activity is affected. I experimented with 3 different fruits. Apple, orange, and papaya. I weighed 2 grams of each of the fruit, and added 3 ml of Jell-O to each one. The 4th test tube didn’t have any fruit. After placing them in the ice bath, I checked for solidification after 3, 6, and 9 minutes respectively. This experiment was also tried with canned fruit and strong acid HCL (Hydrochloric Acid) and a strong base NaOH (Sodium hydroxide). The fresh fruit supported my hypothesis as Jell-O didn’t solidify immediately. Apple seemed to contain less of the enzyme as the Jell-O in this test tube solidified first. The Jell-O in the canned fruit also solidified proving that canning process destroys the enzyme. Several foods contain an enzyme that will prevent Jell-O from solidifying. Canned fruits could be used in making Jell-O.

INTRODUCTION

           Fruit enzyme experiment was carried out to find how enzymes like Bromelain, and Papain found in fruits have an affect on the solidification of gelatin. Jell-O contains gelatin which is made up of a processed protein called collagen. Many animals and humans have collagen. It is a big molecule that is found in the skin, and bones. At room temperature, the gelatin contains triple helix structure. The amino acids in this helix, are held by weak bonds. When hot water is added, it breaks up the bonds and the helix falls apart. The polypeptide chains containing the amino acids float in the liquid. When you chill the Jell-O, the chains try to get together, but are formed incompletely with air inside them. This is what gives Jell-O its jiggly form.


MATERIALS/METHODS

2 balances
2 weigh boats
2 test tube racks
Test tubes (4 per rack)
Test tube brushes to clean tubes
(2) 5 ml Serological pipets
(2) 250 ml beakers for water/ice baths
(2) 60 or 80 ml beakers for Jell-O transfer
Crushed ice
Materials off to the side:
1000 ml beaker
500 ml beaker
Long-handled mixing spoon
Chopped fresh pineapple, kiwi, orange, apple, papaya
Canned pineapple
Jell-O (small box)
30 ml bottle of 1M HCl
30 ml bottle of 1M NaOH
(2) 1 ml graduated pipets
Several weigh boats to transfer fruit
Several spatulas for fruit

Part I: The effect of fruit enzymes on Jell-O

1. I labeled my test tubes 1 – 4 and  fill a 250 ml beaker with ice. Leave just enough room in the beaker for the four test tubes.

2. I Chose  three fresh fruits from the selection. I weighed out 2 grams of each fruit type and added it to one of the test tubes (note which one in the table below). The last tube will have no fruit.

3. I  added 3 ml of Jell-O to each of the four test tubes. I made sure the liquid Jell-O completely covers the fruit. I  gently swirled the tubes, then placed them into an ice bath.

4. Three minutes after each test tube was placed in the ice bath, I  pulled it out to check if the Jell-O had solidified or not. I  recorded my data after 3, 6, and 9 minutes.

Part 2: The effect of canning fruit on enzymatic activity

1. I retrieved my test tubes 1 – 3:

2. I weighed out 2 grams of both fresh and canned pineapple and add it to two of the test tubes (note which one has which fruit in the table below). The last tube will have no pineapple.

3. I added 3 ml of Jell-O to each of the three test tubes. I made sure the liquid Jell-O
completely covers the fruit. I gently swirled the tubes, then placed them into an ice
bath.

4. Three minutes after each test tube was placed in the ice bath, I pulled it out and checked
if the Jell-O has solidified or not. Slightly tilting the tube at an angle helped
me with my analysis. I recorded my results at 3, 6, and 9 minutes.

Part 3: The effect of HCl & NaOH on enzymatic activity:

1. I retrieved my test tubes 1 – 3.
2. I weighed out 2 grams of fresh pineapple and added it to each test tube.
3. I added 1 ml of 1M HCl to one tube and 1 ml of 1M NaOH to the other tube (note
which one is which). I let the mixtures sit for 5 minutes.
4. I added 3 ml of Jell-O to each of the three test tubes. I gently swirled the tubes, then placed them into an ice bath.
5.I checked the results after 3,6,9 minutes.

RESULTS

Part 1 Results

Tube Variable (type of fruit) Time tube put in ice bath Condition of Jell-O after 3 minutes Condition of Jell-O after 6 minutes Condition of Jell-O after 9 minutes
1.) Orange 11:48 Still liquid slightly solid Solid
2.) Apple 11:48 slightly solid near solid hard solid
3.) Papaya 11:48 Still liquid nearly solid solid
4.) No fruit 11:48 still liquid nearly solid solid

Part 2 Results

Type of variable(type of fruit) Time tube put in ice bath Condition of Jell-O after 3 minutes Condition of Jell-O after 6 minutes Condition of Jell-O after 9 minutes
1.) Fresh 2:15 Liquid Liquid Liquid
2.) Canned 2:15 Liquid Liquid Solid
3.) No Fruit 2:15 Liquid near solid Solid

Part 3 Results

Type of variable (what was added?) Time tube put in ice bath Condition of Jell-O after 3 minutes Condition of Jell-O after 6 minutes Condition of Jell-O after 9 minutes
1.) HCL 8:31 Liquid Liquid Liquid
2.) NaOH 8:31 Liquid Liquid Slightly Solid
3.) No Acid

DISCUSSION AND CONCLUSIONS

In Part 1 of my experiment, apples seem to solidify slightly after 3 minutes, while the Jell-O in other test tubes were still liquid. After 6 minutes, apple, papaya, and the test tube with no fruit had Jell-O that was nearly solid. After 9 minutes, the test tube containing apple was a hard solid. The fruits clearly had the enzyme acting on gelatin.

In Part 2 of my experiment, the test tube containing canned fruit solidified after 9 minutes, while the one containing fresh fruit was still a liquid even at 15 minutes. When tested with HCL and NaOH, both the test tubes containing Jell-O solidified at about 12 minutes. In my understanding, the test tube with fruit should have not solidified or taken much longer than 9 minutes. This makes me think that the enzyme might have been diluted because of the juice. The ripeness of the fruit could be a factor. It could be possible that the food coloring and the sugar of the Jell-O may have affected enzymatic activity. In part 2 and 3 of my experiment, I learned that extreme temperatures and pH conditions can render the enzyme ineffective.

APPLICATIONS

Enzymes are widely used in the food industry. They can either break down or build up reactions. They are used as meat tenderizers to produce corn syrup, break down of lactose in  whey and other alcoholic drinks.

REFERENCES

1.) www.semd.org/Abstracts/sampleAbstracts.htm

2.) http://mnhe.com/biosci/genbio/maderinquiry/writing.html

3.) fruit.enzyme.lab.pdf

4.) www.sciencebuddies.org/science-fair/project-abstract.shtml

5.) www.houston-enzymes.com/learn/articles/enzymes-and-their-applications-in-food.php

 

 

 

 

 

 

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