Research Proposal Exemplar #4

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29 Οκτ 2013 (πριν από 3 χρόνια και 7 μήνες)

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Literature Review


The effect of n
utrients on the growth
rate
of yeast

Yeast is
a

unicellular
fungus

that is capable of transforming carbohydrates into
alcohol and carbon dioxide (
fermentation
)
.
This organism reproduces by fission
,

meaning
one whole sepa
rates into two. Yeast is very commonly used in bread making because the
carbo
n dioxide released by it
is necessary for the dough to rise.
In order for yeast to grow
and reproduce, certain conditions are needed. Among them figure the existence of food
(carb
ohydrates), moisture, and warm temperatures.

The existence of carbohydrates is the first condition needed in order for yeast to
reproduce. Through them, yeast feeds on monosaccharides and breaks down sucrose,

maltose
,

and sometimes even starch into glucos
e

(fructose is also successfully used up)

to
be able to convert them
mostly
into water
. Ethanol is a product of fermentation but this
alcohol evaporates at

low temperatures which prevents the bread from being alcoholic.

Carbon dioxide is also a product and

when combined with water it will cause a carbonic
acid solution.


The mo
s
t common artificial sweeteners
in Mexico
are aspartame

(Canderel),

sucralose (Splenda)

and saccharin (Sweet’n Low).

Saccharin is the oldest of the artificial
sweetener
s

discovered
i
n late 1800s; it is the chemical benzo
-
sulphinide, has no food
energy and is about 300 to 500 times sweeter than regular sugar
.

Despite this fact
Saccharin has no energetic source (calories).

Aspartame

is
made by an amino acid and a
methyl ester
: aspartic
acid and phenylalanine

respectively.
These
components can also be
found in protein rich food
s

and beverages
. Aspartame (Canderel) contains the minimal
energetic source of “0.1 calories”.

Finally,
sucralose is a derivation of sugar that has
undergone a mult
i
-
step process in which three hydroxides are substituted by three
chlorine atoms.
Sucralose (Splenda) does not have any energetic content.

There have been experiments testing the effectiveness of different artificial
sweeteners in the growth of yeast. An e
xample of this is an experiment performed by
David A. Katz called “HOW YEAST WORKS”. In such experiment the results
concluded that artificial sweeteners do fulfill the purpose as an energy source for yeast

therefore affecting its growth and exertion of car
bon dioxide. However, this result seems
dubious due to the fact that some of the artificial sweeteners tested (saccharine and
aspartame) do not contain any caloric source for the reaction to take place. A flaw found
in Katz’s experiment is that the product
ion of yeast was only tested in one way and only
once. Therefore ambiguous results could have occurred.

In
order for our experiment

to be accurate we have concluded that it would be
appropriate

to use

a pH meter to measure the amount of Co2 released.

We h
ave chosen
this method because CO2 becomes carbonic acid in water and therefore the pH will
indicate the amount of CO2 released demonstrating how well the fermentation reaction
has taken place

(the lower the pH the more CO2 released)
.
Since aerobic respira
tion is the
first primary reaction that would take place in the case that there was oxygen then t
he
fermentation will occur in a closed beaker
, this way

the 02 will be consumed
first. When
the oxygen is completely used then the yeast will proceed to the ca
rbohydrates through
fermentation. To be able to know how that oxygen in all of the different samples is the
same the same amount of space will be left empty.


Thr
ough implementing several trials

we will
reduce the margin of error to the
least possible
. Th
erefore we will be able
come up with more conclusive results that
determine which artificial sweeteners serve the purpose of baking better.

This experiment will determine, through different accurate testing, which artificial
sweeteners

influence more seve
rely the production of yeast.
Therefore our research will
help people to accurately decide which sweeteners to use while baking

or drinking
,
especially

those with diabetes and other carbohydrate related illnesses

who need to care
for the amounts of calorie
s and carbohydrates that products contain
.

As a result
companies may be able to successfully integrate the best sweetener into their products to
expand the market to calorie
-
counting subjects.

This is necessary because even though
some studies have been de
veloped in the fields of this research proposal, we feel that
none of th
em provide unambiguous results.

One of the main uses of yeast is bread
-
making. Bread has been a very influential
and elemental food through all history. Since the time of the Egyptians

bread has been a
key factor in the fight against famine

because of its low cost and easy production. Yeast
was identified as the agent causing alcohol fermentation and dough rising in the 1860s by
Lewis Pasteur. The brewing of beer has been done as long a
s bread and it is believed that
bread and beer are byproducts of each other. Egyptians considered brewing as a
sacrament. Through history beer has been a very important part of the human diet.


E
x
perimental Design


The experiment
w
ill be carried on durin
g the co
u
rse of one full day and the conclusion
w
ill be drawn on the same day.
The steps taken will be the following:


1.

All the materials will be drawn and assembled in the correct order.

2.

The Erlenmeyer Flasks will be labeled according to their correspon
ding samples
(sugar, Canderel, Splenda, or Sweet N’ Low).

3.

The artificial sweeteners will be placed in the beakers. The amount of sweetener
to be used will be decided by the proportion drawn to 14 teaspoons of sugar.

E.g. One Splenda package equals two su
gar teaspoons (In sweetness). Therefore 7
packages of Splenda will be used.


4.

After this into each beaker (already containing the sweetener) will be poured the
containing of one yeast package (11g).


5.

Next we will fill each Erlenmeyer flask w
ith the same amount of water. (We will
assure that all the water has the same temperature. This will be done in order to
eradicate any weaknesses of the experiment.) After doing this we must proceed to
cover the flasks as quickly as possible in order to al
low the O2 to consume and
therefore give place to the reaction of fermentation.


6.

Next we will allow the mixtures to rest for 30 minutes and after that we will
proceed to measure and record the pH of each solution with the pH meters.

7.

Finally we will analy
ze the data and place it into understandable clusters,
statistics, and graphs.



Dependent Variable:


a)

The pH of each solution


Independent Variables:


a)

Sugar

b)

Splenda

c)

Sweet N’ Low

d)

Canderel


Control Variables:


a)

Temperature of the water

b)

Room Tempera
ture

c)

Beakers


d)

Yeast Brand


Previous experiments on this field have overlooked the possibility of measuring the pH in
order to determine the production of CO2. Therefore they have measured CO2
production through more inaccurate measures which take away reli
ability from the
experiment. We will also include several trials in order to eradicate any misleading
results.

Sample Selection


Overall, through our experiment, we will find out which artificial or natural
sweeteners serve the purpose of cooking better
without contributing any carbohydrates.
This will be helpful for diabetic and other patients with carbohydrate related illnesses.
Therefore, using our data and after retrying our experiment several times, we may be able
to find a solution for all of those
who must count carbohydrates and calories but at the
same time find the irresistible the arts of eating and drinking.


For this reason we have considered appropriate to test artificial, processed, and natural
sweeteners. Among them stand:


1.

Splenda® (One

of the most commonly used artificial sweeteners today and
therefore the perfect target for experimentation)

2.

Canderel® (A popular but controversial sweetener due to its content of
Aspartame. Despite this fact it could prove efficient and overcome its major

adversary Splenda.)

3.

Sweet N’ Low® (Also one of the most popular artificial sweeteners used today
which could prove to be better than its adversary products and regain the market
that it has lost lately.)

4.

Honey (One of the naturist’s favorites but its perf
ormance has been questioned.
Therefore it is important to test it.)

5.

Sugar (The common sweetener and therefore the basis for comparison with all the
other products.)

6.

Maple Syrup (A product commonly used as a substitute for honey but which is
thought to cont
ribute many carbohydrates and calories. Therefore we have
considered important to test its efficiency and to use it as a basis of comparison
and reference too.)

The sample size for each of these products will be proportioned to the sweetness of
two sugar
teaspoons (14g). Therefore for Splenda, Canderel, and Sweet N’ Low we will
use seven packages which contain about 1g each. For sugar we will use 14 teaspoons and
for honey and maple syrup we have agreed on using ¾ of the quantity used for sugar due
to the
fact that these are more concentrated than sugar itself.



All of the samples will be tested three times and the results will be compared in order
to reduce the margin of error. In addition to this we will also use mean, mode, and range
to evaluate the d
ata. At the end of the experiment, along with the conclusion, the data will
be collected in understandable clusters which allow the better understanding of the data
and reinforce its reliability.




Data Collection


The variable to be measured in
this exp
eriment will be the pH of the solution that
will occur after the fermentation of the different sweeteners. The fermented solution is
expected to be carbonic acid (H2CO3) because of the CO2 released will combine with
water.

The instrumentation needed to me
asure the pH of a solution
could b
e litmus paper
but in this case a pH meter would be more accurate thus it is the instrument we will use.
The pH meter is more accurate because it gives more precise values of the pH and its
more sensitive to small changes
of pH. Also the pH meter provides a quantitative value
and the litmus paper would only provide a qualitative value.

The measurement will be taken after the 6 samples have undergone the process of
fermentation (we will leave the samples ferment for 30 minut
es).

The process in order to measure the pH is the following:

1.

Calibrate the pH sensor.

i.

Prepare an acidic solution of known pH.

ii.

Introduce the pH sensor into this solution.

iii.

Read the pH given by the sensor.

iv.

Compare it with the known pH of the solution if the
y are the same then
the pH sensor is calibrated.

v.

If they are not. Do the same previous 4 steps with a different solution
and take the pH again.

vi.

If the margin of error is the same, then this margin can be modified in
each reading of the test. (e.g. The firs
t solution that you prepared had a
known pH of 3 and the pH sensor marked 4.5 then you prepare another
solution of known pH of 2 and you use the pH sensor again on the
second solution and it reads 3.5. We know that the error is of plus 1.5
pH units, theref
ore to each of our readings we will add 1.5 units to get
the real pH)

2.

Open the Erlenmeyer flask in which the samples of the fermented solution
are.

3.

Let the pH sensor rest in the sample for 10 seconds.

4.

Read and record the measurement provided by the instrum
ent.



Each sweetener will be tested three times (the same amount of each substance will
be fermented three different times) in order to have more accurate results. In our charts
we will record the pH of the solution that is caused by the fermentation of
each
sweetener.

pH of fermented solutions

(each sweetener will be tested 3 different times)







Average pH


(1
st

pH recorded plus the 2
nd

pH recorded plus

the 3
rd

pH recorded divided by three)




Range of pH


(The highest pH recording minus the lowest pH recording)





Mode of pH

(The pH value that was recorded most often)


Analysis


In order to obtain more accurate results we will find the mean of each sweeteners
fermented 3 fermen
ted samples. For example (hypothetically) the first trial of fermented
table sugar solution read
2.5 pH units

and the second trial of sugar read 2. 70 pH units
and the third trial of sugar read 2.3 pH units. In this case we will add 2.5 plus 2.7 plus 2.3
w
hich will be equal to 7.5 which we will divide by three to find the average that would be
2.5 pH units. The before stated process will also be carried out for the Splenda samples,
trial

Sugar

Canderel®

Splenda®

Sweet

N’ Low®

Honey

Maple
Syrup

1
st

trial







2
nd

trial







3
rd

trial








Sugar

Canderel®

Splenda®

Sweet N’
Low
®

Honey

Maple
Syrup

pH








Sugar

Canderel®

Splenda®

Sweet N’
Low®

Honey

Maple
S
yrup

pH








Sugar

Canderel®

Splenda®

Sweet N’
Low®

Honey

Maple
Syrup

pH







Sweet N’ Low samples and Canderel samples. We will also find the mode and ra
nge of
the three trials. Continuing with the sugar example, in that case the mode would not
appear since there is no pH value that occurs more than once and the range would be 0.4.
The range is obtained by subtracting the lowest value in a set of numbers b
y the highest
value, in the sugar example the range would be 2.7 minus 2.3 that equals 0.4.



Averaged pH for Samples




In the x axis there will the different sweeteners and in the y axis we have pH.



Range of pHs




In the x axis there will the diff
erent sweeteners and in the y axis we have pH.




Mode of pHs


In the x axis there will the different sweeteners and in the y axis we have pH.








Comparing Trial 1, Trial 2 and Trail 3














In this graph the bars from each separate nutrient a
re expected to be same which would
mean that our experiment was accurate (The blue, purple and beige bars from sugar are
expected to all be about the same height, this would mean our experiment was accurate
and reliable). In the x axis there will the diff
erent sweeteners and in the y axis we have
pH.

Budget


Product

Price

4 pH meters

3
50 pesos

2
Yeast

boxes

17

pesos

Splenda

34 pesos

Sweet N’ Low



灥s潳

Can摥rel



灥s潳

pugar Eregular)

ㄸ⁰Ns潳

㐠4rlenmeyer flas歳

㄰〠灥s潳 each

tater

〠灥s


Tri灬e Beam
Balance

㔰⁕pa

Therm潭eter

㈰〠灥s潳


T潴al a灰p潸imate C潳tW

␱㈸〠
p
es潳
give 潲⁴a步)


Ethics


The whole experiment is based upon finding which sugar substitute efficiently
accomplishes to carry out sugar’s basic purposes of the ferm
entation of
yeast. This,

we
will be able to inform the public about which artificial sweetener that is better for diabetic
and overweight patients when used in the regular basis for things such as cooking and
baking. Therefore our experiment results aim to

good. In addition to this our experiment
will be scientifically valid because the technique we are using to determine the
production of carbonic acid, which is a sign of fermentation, is very accurate (measuring
pH which influences the yeast reaction). Th
erefore our results are 100% reliable and can
be trusted by the public.

In this experiment no animals nor humans will be used so there will be no harm of
ay kind to this species. Since yeast is a living organism it will be harmed to a certain level
but we

don’t consider an ethical problem since yeast has been used since the Egyptians to
make bread. The use of yeast for fermentation and bread, beer and wine making is like
the kill of animals for human food, necessary. Most people are comfortable with eating

bread and drinking beer and wine therefore the yeast usage should not be a problem.


Timeline




Day 1
-

Go buy the materials needed.

Day 2
-

Perform the experiment and record the observations.

Day 3
-

Begin Lab Report.

Day 4
-

Continue to do Lab Report.

Day 5
-
Continue to do Lab Report.

Day
6
-

Ask final Questions to Mr. Balog.

Day 7
-

Turn in final draft.





























Cites for Research Proposal


1.

Lewis, Eddie. "The Effects of Sugar on Yeast Reproduction." Fall 2005 1. 16 Sep
2008
<http://www.
colorado.edu/eeb/courses/1230jbasey/abstracts%202005/33.htm>.

2.

"Yeast on the Rise."
Microbe World
. Creators of the Future. 16 Sep 2008
<http://www.microbeworld.org/resources/experiment/pgs62
-
65.pdf>.

3.

McNeil Nutritionals, "Spelnda FAQs."
Splenda No Calorie S
weetner FAQs

2008
1. 16 Sep 2008
<http://www.splenda.com/page.jhtml?id=splenda/faqs/faqmain.inc>.

4.

Campbell, I.

"What

are yeasts?."
Yeast Genome
. Yeas Genome. 16 Sep 2008
<http://www.yeastgenome.org/VL
-
what_are_yeast.html>.

5.

"Question and Answer Archive."
Sc
ience and Plants for Schools (SAPS)
. 24 Jan
2008. SAPS Scotland. 16 Sep 2008 <http://www
-
saps.plantsci.cam.ac.uk/records/rec358.htm>.


6.

Baker, Ron. "Yeast and Fermentation ."
Ask A Scientist Molecular Biology
Archive
. 17 Dec 2004. Newton BBS. 16 Sep 2008
<h
ttp://www.newton.dep.anl.gov/askasci/mole00/mole00559.htm>.

7.

"Artificial Sweeteners: No Calories ... Sweet!."
US Food and Drug
Administration
. Aug 2006.
FDA. 16 Sep 2008
<http://www.fda.gov/fdac/features/2006/406_sweeteners.html>.

8.

Katz, David. "HOW YEAST WO
RKS." 1997. 28 Sep 2008
<http://www.chymist.com/yeast.pdf>.

9.

"Facts."
Aspartame Information Center
. 2006. Calorie Council Control. 28 Sep
2008 http://www.aspartame.org/aspartame_facts.html
.

10.

"Yeast on the Rise."
Microbe World
. Creators of the Future. 16 Sep
2008
<http://www.microbeworld.org/resources/experiment/pgs62
-
65.pdf>.

11.

"Artificial Sweeteners: No Calories ... Sweet!."
US Food and Drug
Administration
. Aug 2006.
FDA. 16 Sep 2008
<http://www.fda.gov/fdac/features/2006/406_sweeteners.html>.

12.

"Customer Servic
e & FAQs."
Splenda
. 2008. Splenda.
28 Sep 2008
<http://www.splenda.com/page.jhtml?id=splenda/faqs/faqmain.inc>.

13.

"Canderel preguntas frequentes."
Canderel
. 2008. Canderel.
28 Sep 2008
<http://www.canderel.com.mx/faq.php>.