Saturday, 28 July 2012
Failed experiment
The reason for the failure of the first experiment was due to difficulty in finding the right experiment procedure. I tried out once, however, it failed badly, lasting only about 1 to 3 secs. Therefore, a new experiment was thought of.
The references
I also made other references of the journals of the food science in the National Library, from the Lee Kong Chian Reference Library.
The process of doing experiment
The different starch and the egg |
When testing for the thickening measuring the length after 6 hours |
Wheat Starch |
tapioca starch |
corn starch |
potato starch |
testing for the difference between sugar and salt (the mixture) |
Egg
cartoon 1
Tapioca
2 teaspoon salt
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Wheat
1 teaspoon sugar
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tapioca
1 teaspoon sugar
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potato
1 teaspoon sugar
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corn
1 teaspoon sugar
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Potato
2 teaspoon salt
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Wheat
2teaspoon sugar
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Tapioca
2teaspoon sugar
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potato
2teaspoon sugar
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corn
2teaspoon sugar
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Egg
cartoon 2
egg
2teaspoon sugar
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egg
2 teaspoon salt
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corn
2 teaspoon salt
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wheat
2 teaspoon salt
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Egg
1 teaspoon sugar
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Egg
1teaspoon salt
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The background research
When two molecules react
chemically so that there is a release of energy (an exothermic reaction), that
energy sometimes manifests itself not as heat but as light. This occurs because
the energy excites the product molecules into which it has been funneled. A
molecule in this excited state either relaxes to the ground state, with the
direct emission of light, or transfers its energy to a second molecule, which
becomes the light emitter. This process is referred to as chemiluminescence.
The originally green, now multicolored, commercially made "light
sticks" (often in the form of bracelets and necklaces) work in this way,
utilizing the (exothermic) reaction of hydrogen peroxide with an oxalate ester .
This oxidation reaction produces two molecules of carbon
dioxide (CO 2 ), and the released energy is transferred to
a fluorescent dye molecule, usually an anthracene derivative. Light sticks were
developed by the U.S. Navy as an inconspicuous and easily shielded illumination
tool for special operations forces dropped behind enemy lines. Besides their
use as children's toys, they are also used extensively as a navigation aid by
divers searching in muddy water.
These light sticks glow
as a result of the energy released by a chemical reaction.
Chemiluminescence is
also found in fireflies. The male firefly uses the reaction of a luciferin
substrate and the enzyme luciferase with oxygen, with adenosine
triphosphate (ATP) as an energy source, to create the illumination it
uses to attract a mate. Because the detection of very minute amounts of light
is possible, chemiluminescence and bioluminescence have become the basis of
many sensitive analytical and bioanalytical techniques or assays used to
quantify particular compounds in samples. Indeed, the use of these techniques
is broad enough to justify the existence of a journal devoted to them,
the Journal of Bioluminescence and Chemiluminescence.
In 1669 Hennig Brand, a
German alchemist, was attempting to recover, by means of intense heat, the gold
he hoped was lurking in human urine. The waxy white substance that he did
retrieve, which glowed green when exposed to air, was in fact elemental
phosphorus.
The emission of light
observed by Brand was actually chemiluminescence. The light arises from
PO 2 molecules in an excited state. This excited state of
PO 2 is brought about by the reaction between PO and
ozone, which are both intermediates in the fundamental
reaction between oxygen in air and P 4 vapor evaporating
from the solid white phosphorus. It is unfortunate that the chemiluminescent
glow of phosphorus gave rise to the term
"phosphorescence."
Scientifically, phosphorescence is a process whereby absorbed photons are
emitted at a later time, as exemplified by the glow of a watch face in the dark
after its earlier exposure to light.
Luminol
(3-aminophthalhydrazide) is used in a commercially available portable device
called the Luminox that measures minute concentrations (parts per billion) of
the pollutant nitrogen dioxide in air. Luminol is also used frequently in
laboratory demonstrations of the chemiluminescence phenomenon. Luminol-mediated
chemiluminescence is the result of an oxidation reaction. The oxidation
proceeds in two steps, which ultimately lead to the production of the
aminophthalate anion in an excited state and the elimination
of water and molecular nitrogen. The formation of the strong triple bond (N≡N)
is a major factor in the release of energy in the form of light.
Probably the simplest
chemiluminescent reaction (and one that has been studied extensively) is the
reaction between nitric oxide , NO, and ozone, O 3 .
The reaction (with about 10% efficiency) yields nitrogen dioxide in an excited
state (NO 2 *)
NO + O 3 =
NO 2 * + O 2
NO 2 *
= NO 2 + h ν
The reaction was
developed in the early 1970s as a specific and instantaneous method to detect
nitric oxide in the exhaust of automobiles. This use of chemiluminescence
rapidly led to application of the same phenomenon to monitor the presence of NO
in the atmosphere. Both applications continue in use. Ozone can easily be
produced by passing dry air or oxygen through an electric discharge. The
ozone-containing stream and the sample to be evaluated are mixed in a dark
chamber adjacent to a photomultiplier tube, and the chemiluminescence signal
that is produced is amplified. These devices are capable of monitoring NO
levels ranging from parts per trillion to thousands of parts per million; an
individual instrument can sometimes measure concentrations extending across six
orders of magnitude.
The familiar yellow glow
from a natural gas or wood-burning flame is not the result of
chemiluminescence, but is due to bright, red-hot particles of carbon soot. The
blue, green, and other colors produced when metals are put
into flame can indeed be ascribed to chemiluminescence; in these instances the
luminescence is accompanied by heat production.
According to information
provided by the Harbor Branch Oceanographic Institution in Ft. Pierce, Florida,
more than 90 percent of organisms living in the oceans at depths from 200 to
1,000 meters (656 to 3,281 feet) use chemiluminescence for activities such as
attracting prey and avoiding predators. Light from the sky is quite weak at
those depths; a fish that emits a dim glow from its lower parts could become
invisible from below, while a fish without this capability would appear as a
dark shadow.
Donald H. Stedman
Planning Process of the the experiment
Planning for the experiment
Area of
experiment- measuring the duration of phosphorescence can last
when exposed under Uv rays.
w Find
UV light/ Uv lamp to provide the UV rays needed.
w Measuring
the duration the glow-in-the-dark can last in the dark after being exposed to
UV light.
w Find
the phosphorescence material
w Find
the difference between flouroescence and phosphorescence
Area of
experiment –measuring if the amount of chemical in the light stick
would allow it to last longer
w Find
the chemical in the light stick
w Find the
ratio of the chemical needed and the effect of each of them when combined.
Proposal for the chemiluminescence
A
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Observations made
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I
observed that light stick in the chemiluminescence
enables the light stick to last longer than glow-in-the-dark that phosphorescence
is present in.
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B
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Research Question
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Does
Chemiluminescence last longer than phosphorescence
exposed under Ultraviolet
Rays?
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C
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Hypothesis statement
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Chemiluminescence last longer
than phosphorescence exposed under Ultraviolet rays.
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D
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A short summary of research done on the area of
investigation
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Research
shows that phosphorescence exposed under Ultraviolet rays
last longer than phosphorescence under normal light. Chemiluminescence occurs
due to chemical reaction while phosphorescence occurs only when it absorbs
the radiation, and then it re-emits
the radiation
at lower intensity for up to several hours after the original excitation.
Phosphorescence
Phosphorescence occurs
when energy in light waves is absorbed by a phosphorescent material and later
released in the form of light, at a very slow rate. This slow release of
light energy is what causes the glow-in-the-dark sticker to continue glowing
over a period of time.
When ultraviolet light is absorbed by the phosphorescent material, electrons in the atom become"excited". These electrons will eventually return to their normal energy levels, gradually. It is during this gradual process of electron state "degradation", that the material is seen to glow.
Chemiluminescence- present in light sticks
Lightsticks or glowsticks are used by
trick-or-treaters, divers, campers, and for decoration and fun! A lightstick
is a plastic tube with a glass vial inside of it. In order to activate a
lightstick, you bend the plastic stick, which breaks the glass vial. This
allows the chemicals that were inside the glass to mix with the chemicals in
the plastic tube. Once these substances contact each other, a reaction starts
taking place. The reaction releases light, causing the stick to glow!
Chemiluminescence is the production of light from a
chemical reaction. Two chemicals react to form an excited (high-energy)
intermediate, which breaks down releasing some of its energy as photons of light (see glossary for all terms
in bold) to reach its ground state
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E
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Bibliography (Please refer to RS Students’ Handbook in RS Folder on
Inet regarding APA Style Format)
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Friday, 27 July 2012
Vitamin content in potato (other ideas)
Abstract
You have most likely witnessed the change that occurs as a banana
ripens It changes from green and relatively hard to yellow and soft. The flavor
also changes, from bitter to sweet. What happens during ripening? One big
change is the increase in sugar content. In this food science fair project, you
will measure how the sugar content of a banana changes as it ripens.
Objective
Use a refractometer to measure sugar content in ripening fruit.
Introduction
Ripening is a process in fruits that causes them to become
sweeter, softer, and less green. The process of ripening is controlled by the plant hormone called ethylene, which is
a gas created by plants from the amino
acid calledmethionine. A plant hormone is a chemical that regulates growth and other
processes. Storing fruit in a closed container keeps the ethylene from drifting
away and can increase the rate at which the fruit ripens. Ethylene increases
the intracellular levels of certain enzymes in fruit. Enzymes are
proteins that make certain chemical reactions occur faster than they normally
would. The key enzymes involved in fruit ripening are amylase andpectinase. Amylase breaks down starch to produce simple sugars, so is responsible for the increasing
sweetness of a ripening fruit. Pectinase breaks down pectin, a
substance that keeps fruit hard, so is responsible for the increasing softness
of ripening fruit. Other enzymes cause the color of the fruit to change by
breaking down chlorophyll (which is green) and replacing it with pigments that are yellow,
red, or other colors.
Measuring the amount of sugar in ripening fruit is a critical step
in deciding when to harvest certain kinds of fruit. The sugar content of grapes
that are harvested to make wine, for example, is routinely checked during the
grapes' development. The instrument used to measure the sugar content is called
a refractometer. A refractometer takes advantage of the fact that the higher the
amount of sugar dissolved in the juice of a grape, the more the juice will
cause a beam of light to bend, or refract. Actually, any dissolved solid will increase the refractive index of a
solution. Because the major dissolved solid in fruit juices is sugar, the
refractometer reading is a measure of dissolved sugar.
There is also a special unit to measure the amount of sugar that
is dissolved in a solution: degrees Brix. Degrees
(°) Brix is a
measurement of the dissolved sugar-to-water ratio of a liquid. It is measured
with a refractometer. A 15°Brix solution has 15 grams (g) of sugar per 100 g of
solution. Or, to put it another way, there are 15 g of sucrose sugar and 85 g
of water in the 100 g of solution. Note that degrees Brix depends on the mass
of sugar and water, and not on the volume of the solution.
Refractometers are easy to use. A few drops of the liquid are
placed on the glass of the refractometer and the cover is closed. You then look
through the eyepiece and read the degrees Brix on the scale that is visible
inside. The amount of sugar in the solution is determined by where the color
changes. Figure 3 shows the reading in a refractometer for a solution that has about
3.2°Brix. In this food science fair project, you will use a refractometer to
measure how the sugar content changes in bananas as they ripen. Bananas are a
good choice because ripening is accompanied by a clear change in color. This
will allow you to select a variety of bananas at various stages of ripeness for
testing.
Terms, Concepts, and Questions to Start Background Research
- Plant hormone
- Ethylene
- Amino acid
- Methionine
- Enzyme
- Amylase
- Pectinase
- Starch
- Pectin
- Chlorophyll
- Refractometer
- Refract
- Refractive index
- Degrees Brix
Questions
- What is the role
of ethylene in fruit ripening?
- What is broken
down to make sugar in fruit?
- What enzyme is
responsible for making more sugar in fruit?
- Based on your
research, what is the principle of operation of a handheld refractometer?
Materials and Equipment
- Bananas, unripe
(5 per trial; 3 trials)
- Metal dinner
fork and knife
- Dinner plate
- Cheesecloth
- Scissors
- Refractometer,
handheld;
- Lab notebook
Experimental Procedure
1.
To begin, collect five unripe bananas. Choose five bananas that
are similar in size and that are all unripe. The bananas should be as similar
to each other as possible. The pieces of fruit should be unripe when you take
your first reading at the start the procedure and very ripe for the last
reading.
2.
Read the directions that came with your refractometer.
3.
On the day you purchase them, cut off a section of one of the
unripe bananas that is about 3 inches in length.
4.
Place the banana section on the plate and mash it thoroughly with
a fork.
5.
Cut a 6-inch square of cheesecloth.
6.
Place about one-third of the chopped banana in the cheesecloth and
squeeze out a few drops of juice onto the lens of the refractometer.
7.
Squeeze slowly so that the juice has time to flow through the
cloth. As an alternative, you can wipe the surface of the wet cloth on the
glass of the refractometer.
8.
Read the sugar content of the unripe banana. Record the data in a
data table in your lab notebook. Be sure to note the trial number, condition of
the fruit, date, and sugar content (in Brix). Discard the fruit in the
cheesecloth.
9.
Repeat steps 4–7 with the remaining freshly mashed banana two more
times. Use new cheesecloth and banana for each reading. You should have three
separate readings for each piece of fruit.
10.
Repeat steps 4–7 for the remaining pieces of fruit, as they ripen,
as follows. Note: You might want to modify the days on which you take your Brix
readings, depending on how quickly the fruit is ripening.
a.
Day 2: Test the second piece of fruit.
b.
Day 4: Test the third piece of fruit.
c.
Day 6: Test the fourth piece of fruit.
d.
Day 8: Test the last piece of fruit.
11.
Perform the entire procedure two more times. This demonstrates
that your results are repeatable. The tests can be run concurrently.
12.
Average the degrees Brix for each day and record these numbers in
your lab notebook.
13.
Graph the time, in days, on the x-axis and the degrees Brix on the
y-axis.
Variations
- Store the
bananas at different temperatures and compare the rate of ripening.
- Compare the rate
of ripening in bananas that are kept in a sealed container to bananas that
are exposed to the air. To minimize differences between the two batches,
put an equal number of fruit pieces into two identical containers, and
then seal one of them. Make sure the temperature, moisture, etc. are the
same for the two batches of fruit. You could also compare fruit stored in
a closed paper bag to those stored in an open paper bag.
- What happens to
the rate at which the fruit ripens if you store it with other fruit, such
as with a ripe apple or banana? Also, you could compare bruised bananas
vs. un-bruised bananas (bruised fruit produces more ethylene gas).
- Devise a way to
determine how sugar content changes as a fruit of your choice ripens on a
vine.
- For more science
project ideas in this area of science, see Cooking & Food Science Project Ideas.
Credits
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To determine which cooking liquids slow bean softening (other ideas)
Abstract OK, spill the beans, what's your favorite bean-rich food? Burritos? Chili? Or maybe you prefer the spicy Indian stew of lentils, known as dal? But what about fried tofu? Soymilk? Or peanut butter and jelly sandwiches? Did you know those foods come from beans as well? Beans are important to the diets of many people, and in this cooking and food science fair project, you'll learn how the liquid that beans are cooked in affects how quickly or slowly they soften. Objective To determine which cooking liquids slow bean softening and which cooking liquids hasten bean softening. Introduction Peanut butter and jelly sandwiches...classic! If you love this food, you might not realize it, but you're not actually eating tree nuts (like almonds or walnuts) at all! You're eating a bean, also known as a legume. Legumes are small, but powerful sources of nutrition. After the grains, like wheat and rice (from the grass family of plants), legumes are the second most important family of plants in human diets. Their special contribution to human nutrition is protein,which they are able to make thanks to a clever bacteria known as rhizobium. These bacteria get into the roots of the plant and change the nitrogen in the air into a form that the plants can use to make amino acids, the basic building blocks of protein. The protein content in legumes is 2-3 times as great as the protein content in the grasses. Having a reliable source of protein has been critical to the development of human civilizations. Animal protein is often hard to obtain and can be expensive, and protein from grasses is too limited to survive on over the long-term, so legumes have filled that human need for protein in many cultures throughout the world, especially in Asia, Central and South America, and the Mediterranean. They may be small and humble looking, but beans are held in high standing in many societies. For example, some cultures, like those near New Orleans, Malta, Nicaragua, and Italy, believe eating beans on New Year's Day will bring you good luck, and the Romans named powerful families after the names of legumes in the Mediterranean: Fabius was named after the fava bean, Lentulus after the lentil, Piso after the pea, and Cicero comes from the word for chickpea. Legumes provide people not only with protein, but also with B vitamins, iron, some starch (complex carbohydrate), and, in the case of soybeans and peanuts, rich, healthy oils. Their seed coats are indigestible, which means that they are a good source of fiber, and colorful, which means they are full ofantioxidants, which help prevent diseases. Legumes are also high in defensive compounds, which are substances that the plant makes to protect itself. If dried beans are fed to people or cattle raw, or not fully cooked, the beans can make them sick. Cooking removes or disables these defensive compounds, and makes them safe to eat. How are legumes cooked? It depends on the type of legume. A few legumes, like peas and bean sprouts, can be eaten safely fresh (without any cooking). Others with high oil content, like peanuts and soybeans, are safer cooked. Fresh, moist, shell beans in their pods (like green beans) should be simmered, sautéed, or steamed, but only for a few minutes, as they cook fairly quickly. It is the dried, mature bean seeds that require a lengthy cooking time, and these will be the focus of your science fair project. Most beans, with the exception of soybeans and peanuts, are made up primarily of protein and starch. The nutrients are stored inside the bean seed in a part of the bean called the cotyledon, as shown in Figure 1. The two cotyledons are completely surrounded by a tough seed coat, except for the point at which the bean has a little dimple. That is where there is a break in the seed coat and you'll find a little hole or pore called the hilum. The hilum is where the bean seed was attached to the living plant before it was picked and dried. Initially, when placed in water, the dried bean seeds can only absorb water through their hilums. After about 30-60 minutes, though, the seed coats expand and become hydrated. At that point, water can move into the bean through the hilum and the entire seed coat surface. Cooking dried bean seeds in a liquid is necessary to soften the cotyledon cell walls and the starchy granules within them. Dried bean seeds are best cooked in just enough cooking liquid to barely cover them. If you use too much liquid, then the flavor will be weak. Also, it is best not to hard-boil them because the turbulence from the hard boil can damage the seed coats and cause the beans to break up into pieces. A slow simmer (180-200°F) is a better and gentler cooking treatment. Food scientists have learned that several substances added to the cooking liquid can impact the softening of beans. Sometimes, slow softening over several hours is desirable, if, for example, you have a dish that needs hours of cooking to develop flavors and you don't want the beans to fall apart into mush. Other times, faster softening is desired, such as if you need the finished cooked beans more quickly, or if you want a more pureed-like end product. Softening can be slowed by the addition of these substances to the cooking liquid: 1. Acids 2. Sugar 3. Calcium Acids work by making structures called hemicelluloses in the cell wall of the bean seed more stable and less inclined to dissolve in water. Sugars work in two ways: they strengthen the cell walls and slow the swelling of the starch granules within the cotyledons. Calcium also works on the cells walls, cross-linking and strengthening their pectins. So, for example, if you live in an area with "hard water," with high levels of calcium and magnesium, and you use that water for your cooking liquid, you will slow the softening of your beans, and may even prevent them from softening fully. Or, if you add a substance like molasses to your cooking water (molasses is slightly acidic, and rich in sugar and calcium), the molasses will work to slow the softening of beans in four different ways: stabilizing hemicelluloses, strengthening cells walls, slowing the swelling of starch granules, and cross-linking pectins. Softening can be sped up by making the water more alkaline. For example, adding 1 teaspoon (tsp.) of baking soda for every 1 quart (qt.) of water can decrease the cooking time by nearly 75 percent! Baking soda works by helping the hemicelluloses dissolve in water, and it contains sodium, which kicks out the magnesium from the pectins in the cell walls and makes them more readily dissolvable. The disadvantage, though, is that baking soda can give the finished product a slippery or soapy feel and taste. Table salt can also speed up softening, although many cookbooks suggest otherwise. It does initially slow the rate of water absorption, but once that happens, plain salt (in amounts of 2 tsp. per qt.) will speed cooking greatly. Finally, cooking times can be reduced, not by the addition of a substance to the cooking liquid, but by simply presoaking the beans overnight in water. This reduces cooking time by 25 percent or more so that time cooking isn't spent just getting water to the center of the bean. So now you're ready to put some cooking liquids to the test and see which ones result in beans that are tough or tender. Terms, Concepts, and Questions to Start Background Research
Questions
Bibliography
To see some beautiful photos of different beans from around the world, visit this source:
For help creating graphs, try this website:
Materials and Equipment
. Experimental Procedure Presoaking Your Beans 1. Open the bag of beans and dump them into a large container. Add water to the container until the beans are well covered (by at least 1-2 inches of water). Put the lid on the container and place the container on the counter overnight (or for at least 8-10 hours). 2. After they have soaked, examine your beans and write down in your lab notebook your observations about what has happened to them. If you are not going to do any testing right away on your beans, then put them in the refrigerator in the covered container (without draining them). Cooking the Beans Using Your Test Substances 1. When you're ready to begin testing, put ½ cup of fresh water in the saucepan. 2. Add one of your test substances to the saucepan and swirl or stir it gently with a spoon for a few seconds to mix the water with the test substance. 3. Scoop up ½ cup of soaked beans with the measuring cup. Hold one hand loosely over the top of the cup and tilt the cup slightly over a sink to drain the beans, and then add the beans to the saucepan. 4. Bring the contents of the pan just to a boil. 5. Put the lid on the saucepan and turn the stove burner down to its lowest possible setting. The beans and their cooking liquid should be barely simmering. 6. Set the timer and simmer the beans and their cooking liquid for 15 minutes. 7. Turn off the stove, take the saucepan immediately off the burner, and pour the contents into a small bowl. Allow the beans to cool completely on a counter before touching them. Label the bowl with the name of the test substance, using a small sticky note, and set the bowl aside on the counter. 8. Wash and dry the pan. 9. Repeat steps 1–8 for all the bean-softening substances that you are testing. 10. Now repeat step 1, skip step 2, but repeat steps 3–8. The beans resulting from this cooking trial will be your controls. No test substance should be added to the cooking water for this batch. Preparing Your Testing Apparatus 1. With the scissors, cut a slot near the top of a small paper cup, just big enough so that the handle of the cheese slicer fits through it. Be careful with the scissors and ask an adult to help you if you are having trouble. See Figure 3, below. 2. Push the paper cup onto the handle of the cheese slicer through the slot in the paper cup. If the cup slides around too much, then you can use some tape to make it more secure. Observe where the cup is resting on the handle (for example, near the tip, or in the middle) and make note of that location in your lab notebook. As you perform the trials, the cup should always be positioned in the same place. 3. Place the cheese slicer with the paper cup attached on the edge of a table so that when the handle falls downward, the cup does not ever hit the table. Testing Your Cooked Beans 1. Set your cooked bowls of beans side by side on a table or counter and examine them with your eyes and hands. Are there any broken pieces? Have the seed coats fallen off some beans? Pick up one bean from each bowl and squeeze it over a sink between your thumb and forefinger. Does the bean feel soft or firm to you? Write down your observations in your lab notebook. After you squeeze each bean, throw the bean pieces away and wash your hands. 2. In this step, you will determine the best spot on your cheese slicer cutting board for testing your beans. Locations higher up on the cutting board need less pressure to cut through the beans, while locations lower down on the cutting board need more pressure to cut through the beans. You want a spot that is not too much pressure for the softest beans, but at the same time, not too little pressure for the hardest beans. To find the ideal spot, first remove three beans from the bowl that has some of the softest beans that you felt in step 1 of this section. Place one of the soft beans across the groove in the cutting board near the top of the cheese slicer. Let the wire rest against the bean. a. If the cheese slicer wire rests against the bean (without cutting through it), then mark this spot on your cheese slicer with a sticky note, as shown in Figure 3, and go on to step 3. b. If the weight of the handle causes the cheese slicer wire to cut through the bean, remove the bean pieces from the cheese slicer and try another of the same type of soft bean in a different spot on the cheese slicer cutting board. For example, this time place a bean across the groove in the middle of the cutting board on the cheese slicer. c. If the cheese slicer wire rests against the bean (without cutting through it), then mark this spot on your cheese slicer with a sticky note, as shown in Figure 3, and go on to step 3. d. If the weight of the handle still causes the cheese slicer to cut through the bean, remove the bean pieces from the cheese slicer and try yet another of the softest beans. This time, place the bean so that it straddles the groove near the bottom of the cutting board on the cheese slicer. Mark this spot on your cheese slicer with a sticky note, as shown in Figure 3, even if the weight of the handle still cuts through the bean. 3. Now clear your cheese slicer of any bean pieces, but leave the sticky note in place. Remove three beans from one bowl. Place one of the beans in the position indicated by the sticky note. Let the cutting wire rest gently against the seed coat. 4. Begin adding coins or other small weights slowly to the paper cup. Count the coins or weights as you add them. See Figure 4, below. When the wire cuts through the bean, stop adding coins or weights to the small cup and write down the number that you counted in your data table in your lab notebook. If you lost count or didn't keep track, you can dump out the contents of the cup and count the number of coins or weights inside. If the wire never cuts through the bean, then try a bigger paper cup that can hold more coins or weights. 5. Remove the paper cup from the handle and dump out all the coins or weights. Replace the paper cup on the handle. Position it so that it is in the same location on the handle that it was in previously. If the cup becomes torn while taking it off the handle, or putting it back on, then get a fresh paper cup and create a new slot with the scissors. 6. Repeat steps 3–5 for the other two beans so that you have a total of three trials for one bowl of beans. 7. Repeat steps 3–6 for all the bowls of cooked beans. 8. After you are finished testing, throw away and do not eat any of the beans, as they are only partially cooked, and are not safe to eat. Wash your hands after touching the beans. |
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