David Daniel
02/14/2013
FOS 4041L, 12769
Vegetable Preparation Lab Report
Introduction
The purpose of this experiment was to determine the effect that different
cooking methods had on the flavor and texture of vegetables. The different conditions
the zucchini was cooked in were varying pH, saltiness, and time. The zucchini was also
cooked in water as a control in the experiment.
Materials and Methods
The initial step was slicing a large zucchini into 12 equal slices and then dividing
them into 4 different groups; 3 slices to each group. Each treatment was prepared as
follows:
1) ½ cup of water was added to 4 different saucepans of equal size.
2) With the exception of 1 saucepan only containing water the 3 other saucepans
had these different ingredients added to the water:
a)
1/
2
tsp baking soda
b) ½ tsp white vinegar
c) ½ tsp salt
3) Each solution was brought to a boil and then the zucchini was added to them.
Once the zucchini was in the solution they were allowed to cook for 3 minutes
then 1 piece was taken out of each solution and was evaluated for color, texture, flavor.
This evaluation was repeated after the zucchini cooked for 10 minutes.
Results
Each treatment had a significantly different effect on the zucchini the
evaluations for each solution and the time cooked can be seen in Chart 1.
Chart 1
Treatment
None
3 Minutes
10 Minutes
Color
Texture
Flavor
Color
Texture
Flavor
Green
Crunchy
Normal
Green
Slightly
Normal
less
Zucchinni
zucchini
crunchy
Baking
Green
Soft
Salty
Soda
Vinegar
Salt
Dark
Mushy
Green
Very
bitter
Light
Slightly
Slightly
Even
Still
Slightly
Green
crunchy
acidic
lighter
somewhat
more
green
crunchy
acidic
Green
Softer
Salty
Green
Kind of
Salty,
hard and
savory
tough
than
before
Discussion/Q&A
1. Explain why the baking soda produced the reaction that it did (or should have).
Consider color and texture.
Color- The color was less intense and faded.
Texture- The texture was very soft.
Both of these characteristics changed in the vegetables cooked in the baking
soda because the hemicellulose was partially broken down by the basicity of the
baking soda and the pigments in the zucchini became bound to the baking soda,
which made the color less intense.
2. Name three reasons why the use of baking soda should be limited when
cooking vegetables.
If vegetables are cooked in baking soda too long then the flavor will become very
bitter, it will become excessively mushy, and the high pH can destroy some
nutrients.
3. Why did the vinegar produce a color change? Discuss and explain at the
molecular level.
The acidity of the vinegar produced a color change because the pigments in the
zucchini form pheophytins when exposed to an acidic environment.
4. In general, explain what is happening inside the plant cells when vegetables
are cooked.
Whenever plants are being cooked predominately what is happening is that the
pectic substances that make them very tough become soluble whenever heated.
5. What was (or should have been) the effect of salt on the texture of zucchini
when heated? Why?
The zucchini was slightly tougher in the salt solution because the increased
solute concentration retards softening.
6. Consider the Cauliflower Gratin Recipe. Name and discuss one phytochemical
found in this recipe (need reference, 5 sentences max).
Garlic found in this recipe contains the phytochemical ajoene. Ajoene has been
found to be a natural blood thinner. It also is currently being used to treating
blood clotting disorders. Ajoene also has shown to have successful antimicrobial
properties.
Source: http://micro.magnet.fsu.edu/phytochemicals/pages/ajoene.html
7. Consider the canned whole tomatoes that were used. Why is calcium added
during the canning process of whole tomatoes?
Calcium is added during the canning process to maintain freshness and firmness
of the tomatoes.
8. Name the type of juicer (not the brand name) that was used in lab and describe
how it works.
The type of juicer we used was a masticating juicer. The plant material gets sent
through the material where it gets crushed between two rotary blades and goes
through a screen.
9. Name three extraneous variables in the zucchini experiment.
1) Equipment
2) Experimenter
3) Freshness of produce
Conclusion
From the results obtained from this experiment it is extremely apparent that
cooking time and method have a significant effect on the color, texture, and taste of a
vegetable.