Download Mini-Lab - TyamiekeaKaul

Mini-Lab
Chemistry Unit
Investigate Enzymatic Browning
What factors affect enzymatic browning? When sliced, an apple’s soft
tissue is exposed to oxygen, causing a chemical reaction called oxidation.
Enzymes in the apple speed this reaction, producing darkened, discolored
fruit. In this lab, you will investigate methods used to slow enzymatic
browning.
1. Predict the relative amount of discoloration each of these apple
wedges will show when exposed to air. Justify your prediction.
Sample 1: Untreated apple wedge
Sample 2: Apple wedge submerged in boiling water
Sample 3: Apple wedge submerged in lemon juice
Sample 4: Apple wedge submerged in sugar solution
2. Prepare 75 mL of each of the following: boiling water, lemon juice,
and sugar solution in three 250 mL beakers. (There will only be one
lemon juice solution per class, you must share.)
3. Slice an apple into 6 wedges. Immediately use tongs to submerge
each wedge in a different liquid. Put one wedge aside.
4. Submerge the wedges for three minutes, and then place on a paper
towel, skin side down. Observe for 10 min, and then record the
relative amount of discoloration of each apple wedge.
5. Analyze the following questions:
a. How did each treatment affect the chemical reaction that
occurred on the fruit’s soft tissue? Why were some of the
treatments successful?
b. A restaurant owner wants to serve fresh-cut fruit. What
factors might be considered in choosing a recipe and
preparation method.
Apple Lab
Oct 23, 2009
Name:
Tyamiekea Kaul
Problem: (What are you looking for?)
I am looking to see what the apples will do when I submerge them in the
substances.
Hypothesis: (What do you think will happen?)
I believe that the apples will react when they are submersed in each substance
because anything that is put into a chemical will create a chemical reaction.
Materials: (What will you use?)
1. 4 apples wedges.
2. 1 beaker of boiling water.
3. 1 beaker of lemon juice.
4. 1 beaker of sugar solution.
Procedures: (What will you do?)
1. Put one apple in each substance.
2. After 3 minutes, take them out and lay on paper.
3. Watch the apples after you take them out for 10 minutes.
Data/Observations: (What happened?)
After I took the apples out of each substance, I noticed that the air one turned
sort of brown, the sugar one looked new, the hot water one turned a little brown,
and the lemon one looked like it shrunk a little bit.
Analysis: (Answer the questions?)
1. Each apples tissue changed during the process of putting them in each
substance by they all sort of got hard and not as squishy as when you first
cut the apples. Some of the treatments were successful because when
you submerge a substance in something, it’s determined to have a
chemical reaction.
2. If a chef would like to have fresh fruit all the time, I would suggest that he
puts his apples in water and sugar because that is what seemed to keep
the apples fresher longer. I wouldn’t suggest leaving them out and cooking
them in lemon juice.
Conclusion: (Refer to your hypothesis: Were you correct? What were
sources of experimental error? What happened?)
Yes, my hypothesis was correct because I stated that the apples would
change if they were submerged in substances regardless of what the substance
was. Sources of experimental error might have been that the apple didn’t fully
submerge entirely in the substances and that might have effected the results.
The apples had different effects on what happened when they were submerged
in each substance.