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The Effect of Sugar, Stevia, Splenda, and Sweet N’ Low on the Shelf Life of a Pound Cake

Evalyn Neal Cooke and Charlotte Mae Jones 10th Grade

Heathwood Hall Episcopal School 3000 South Beltline Blvd.

Columbia, SC 29201

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Table of Contents

I. Abstract......................................................3

II. Introduction..............................................4

III. Materials.................................................6

IV. Methods..................................................7

V. Results......................................................8 VI. Conclusion..............................................12 VII. Acknowledgements...............................13 VIII. Works Cited.........................................13

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I. Abstract

THE EFFECT OF SUGAR, STEVIA, SPLENDA, AND SWEET N’ LOW ON THE SHELF LIFE OF A CUPCAKE

Evalyn Neal Cooke Charlotte Mae Jones

Heathwood Hall Episcopal School

The purpose of this experiment is to discover the effect of Stevia, Sweet N’ Low, Splenda and sugar on the shelf life of a mini pound cake. This is significant because if large manufacturers need to sell cakes, the information found in this experiment would be necessary for proper knowledge, precautions, and efficiency. The following hypothesis was utilized: if the cupcake is made with a sugar substitute then it will take longer to decompose compared to the cake made with refined sugar. Two trials were run, where the five independent variables−Refined Sugar, Splenda, Sweet N’ Low, Stevia, and Nothing−were placed in Biochambers with a carbon dioxide sensor, an oxygen sensor, and a thermometer. The carbon dioxide and oxygen sensors were attached to the Vernier Loggerpro software that automatically collected data every hour for five days. The temperature was collected manually once everyday. The data were averaged and analyzed showing that the hypothesis was rejected. The cupcake baked with sugar had the lowest decomposing rate. The results were analyzed using a one-way ANOVA test (alpha=0.05). Respectively, this test showed that the only statistically significant differences were found in the oxygen levels between the control and Splenda, and the control and Stevia. However, there was no statistically significant difference for change in both carbon dioxide, temperature, and oxygen levels for all other variables tested.

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II. Introduction Have you ever wondered how long you have to eat a cake? Sure, you can look up

on the Internet what the cake mix’s shelf life is, but what about the actual baked cake? In

this experiment the effects of sugar, Stevia, Sweet N’ Low, and Splenda will be on the

shelf life of a plain mini pound cake will be determined. The Independent variables were

chosen because they are the most well-known and most widely used substitutes. Sugar is

“sucrose, the white crystalline sugar refined from cane or beet juice by stripping away all

its vitamins, minerals, protein, fiber, water, and other synergists” (HPS-Online). White

sugar is a man-made product that causes the pancreas to secrete unnaturally large

amounts of insulin, which is needed to break down the sugars. Large sugar consumptions

will steal nutrients from other places in your body, causing a lack of nutrients, which can

be very harmful. Sugar is the backbone of many diseases today, one of the more serious

ones being diabetes. When consuming sugar, you should always regulate the amount of

intake into the body, but that also goes along with most man made products in the food

industry today, meaning that most, if not all processed foods can be very harmful to the

body. Sucralose, or Splenda, is a sugar replacement that has “678 fewer calories than a

cup of sugar”, so it is promoted as a better way to cook so that there are not as many

calories or carbohydrates as regular refined sugar (splenda.com). It is also used in a high

variety of places for cooking and baking. Sweet N’ Low, or more specifically called

saccharine, is also a commonly used granulated sugar substitute. An all-natural

substance, Stevia, is an herb used in either a powder or liquid form that is “30 times

sweeter than sugar” and is a “safe alternative” to sugar and synthetic sugars (stevia.com).

All sugar substitutes used are safe for diabetics. Diabetics can easily make these recipes,

so they can have a safe and healthy dessert without increasing their blood sugar.

Previous studies by Gelinas, Roy, and Guillet have shown that replacement of

natural cocoa sweetener with a highly processed cocoa powder slowed staling rate in

devil’s food cake (Food Science, 2008). Also, in that experiment, the use of high

concentrations of fats, sugars, and egg whites also slowed the staling rate. The staling rate

was measure by “studying the effects of packaging film water permeability and storage

temperature over time” (Food Science, 2008). The study also shows that staling can be

reduced slightly by using butter instead of shortening and to replace glucose with sucrose.

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This study is helpful to this project because it indicates that shelf life can be affected by

different ingredients that are taken out or replaced, just like in the experiment by Gelinas

and Guillet, the shortening was replaced with butter, and the glucose replaced with

sucrose. In the case of this project, the sugars are going to be interchanged.

The plain pound cake, serving as one of the many constants, is a basic recipe

found in the book, “Easy Recipes with 5 Ingredients or Less”, except one teaspoon of

vanilla will be implemented instead of the one tablespoon of orange juice. This simple

recipe will be used to keep costs low, and keep the other ingredients from affecting the

shelf life.

In this experiment, “shelf life” of the mini pound cake was tested. For the means

of this experiment, “shelf life” is defined as the amount of time it takes for a cake to

deteriorate, or come to a point where it is not sanitary to consume. In determining shelf

life, three tests will be run: CO2 test, and temperature probe test. Results will be collected

and the results will be turned into a rate, which will then be put into a graph.

A CO2 sensor, which will be used in the testing of the mini pound cakes, is a

sensor, which will be run through a PC computer, that measures carbon dioxide gas. The

most common principles of a CO2 sensor are the infrared gas sensor (NDIR) and

chemical gas sensor. For the purposes of this experiment, the chemical gas sensor will be

used (Cardiopulmonary Technologies, Inc., 2005). The CO2 sensor will help determine

the different factors that affect shelf life. The more CO2 found emitting from the cake, the

higher the presence of living microorganisms undergoing cellular metabolism on the

cakes. Kaplan and Reinhold have shown the relationship between CO2 and

microorganisms in their study of photosynthetic microorganisms (Plant Biology, 1999).

When measuring the CO2, the unit parts-per-million will be used for the amount of CO2

in the biochamber. Safe CO2 levels for a room can be range from around 5,000 ppm and

below.

A thermometer, which will also be used in the testing of the mini pound cakes, is

a device that measures the temperature through voltage across a diode. It is said that by

amplifying the voltage change, it is easy to generate an analog signal that is directly

proportional to temperature (Instructables, 2010). As  the  cellular  metabolism  on  the  

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mini  pound  cakes  increases,  the  temperature  in  the  environment  should  also  

increase.  

An O2 probe was used also because if the CO2 levels and the O2 levels have an

inverse relationship. For this experiment, the oxygen units were changed from

percentage to ppm.

A biochamber 1000, which the individual mini pound cakes will be stored in, is a

controlled environment for the testing of the cakes, which is important for the

experiment, so that no other factors affect the shelf life except for the sugar and sugar

substitutes.

This experiment is helpful in telling if it is still healthy and sanitary to eat a cake

that has been sitting out for a two week time period. It also helpful in determining

whether one sugar or sugar substitute in particular could be used over the other and which

prolongs or deteriorates the shelf life.

The purpose of this experiment is to determine the effect of Stevia, Sweet N’

Low, Splenda, and sugar on the shelf life of a mini pound cake. It is hypothesized that if

the pound cake is made with a sugar substitute then it will take longer to decompose

compared to the cake made with sugar; however, the null hypothesis is if the pound cake

is made with a sugar substitute then there will be no difference in the amount of

decomposition compared to the cake made with sugar.

III. Materials 1 oven 1 mixer 2 large mixing bowls 8 sticks of Butter 2 cups of sugar 12 eggs 8 cups of flour 4 tsp. of vanilla extract 2 cups of Splenda 2 cups of Stevia 2 cups of Sweet N’ Low 1 muffin tin 1 oven mitt 1 can of Pam

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5 Vernier O2 censors 5 Vernier CO2 censors 5 Learning Resources temperature probes 5 Cambro Biochamber 1000, Vernier 5 computers equipped with Logger Pro Software, Vernier IV. Methods Experimental Design Diagram: TITLE: The effect of Stevia, Sweet N’ Low, Splenda and sugar on the shelf life of a Pound cake. HYPOTHESIS: If the mini pound cake is made with a sugar substitute then it will take longer to decompose compared to the cake made with refined sugar.

This experiment had five different groups: Sweet N’ Low, Splenda, Stevia, Refined

Sugar, and the control was an empty Biochamber housing only the sensors and

thermometer. The following cake recipe was followed for all groups:

Preheated oven to 350 degrees, creamed two cups of sugar and 2 sticks of butter until

light and fluffy, added three eggs one at a time and beat after each addition, Stirred in two

cups of flour and one teaspoon of vanilla. Poured into greased and floured cupcake pan

(pan makes 12 cupcakes, but only four molds used). Baked for exactly 30 minutes. After

the four cupcakes had been baked, they were set on the counter and cooled for about 30

minutes.

Next, each cupcake was placed in a separate Biochamber on top of a paper towel,

IV: Sugar and Sugar Substitutes  

Sweet N’ Low Splenda Stevia Refined Sugar Nothing  (Control)  

2 Trials 2 Trials 2 Trials 2 Trials 2  Trials  

DV: Shelf Life as measured by rate of CO2 and O2 production, and temperature  

Constants: basic cake recipe, experimenting environment, temperature at which cakes are cooked, time cakes are cooked in oven, container cupcakes are in (Biochamber 1000), distance of cake from sensors  

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which had a carbon dioxide and oxygen sensor and a thermometer attached to the side.

The Vernier Loggerpro software automatically took samples of the current oxygen and

carbon dioxide levels of the cupcake. The software took samples every hour and

temperature was manually collected once everyday. Preceding the first trial, a second trial

was performed following the same procedures as above. Once the data of the two

separate trials had been collected, the means were taken from the data and calculated.

V. Results Table 1: Mean Carbon Dioxide Levels over 112 hours CO2 (ppm) Control Sugar Stevia Sweet N’

Low Splenda

0 hrs. 212.75 563.5 315.75 948 443.5 24 hrs. 229.75 252.5 681 981 482.5 48 hrs. 232.25 600 711 1039 487.5 72 hrs. 505.5 584.5 727 1023 502 96 hrs. 456 510.5 706 1009.5 433.5 112 hrs. 322 348 598 817 296.5

Figure 1: Mean Carbon Dioxide Levels vs. Time

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Table 1 and Figure 1 depict the mean carbon dioxide levels for the cupcakes

baked with sugar, Stevia, Sweet N’ Low, and Splenda, including a control. The highest

range was the Stevia cake with a range of 3.74, and the Sugar cake had the lowest range

with a range of 0.104. The mode was not applicable. The highest mean was the Stevia

cake with a mean of 0.776, and the Sugar cake with a mean of -0.552. the lowest median

was sugar cake with a median of -0.552, and the highest median was the Stevia cake with

a median of 0.776. The Stevia cake had the highest standard deviation at 2.64, and the

sugar cake had the lowest standard deviation at 0.074. The Sweet N’ Low cake has a

higher CO2 level throughout the entire trial than the rest of the sugar substitutes, showing

numbers in the 1000’s where none of the other mini pound cakes did. All of the carbon

dioxide levels were higher at the beginning of the data collection than the control was. A

trend occurs at 72 hours, when the carbon dioxide levels decrease. The sugar cake

dropped dramatically at 24 hours. At 112 hours, the control, sugar, and Splenda cakes all

decreased to around the same carbon dioxide level, but the Sweet N’ Low cake and

Stevia cake ended at higher levels than the rest. There was no statistically significant

difference (p>0.05) for change in the carbon dioxide levels between any of the variables

tested. The data above failed to reject the null hypothesis that if the mini pound cake is

made with a sugar substitute then it will not take longer to decompose compared to the

cake made with refined sugar, and the data did not support the hypothesis.

Table 2: Mean Oxygen Levels over 112 hours O2 (ppm)

Control Sugar Stevia Sweet N’ Low

Splenda

0 hrs. 16113.5 175489 197992.5 235061 206371 24 hrs. 160515 191584.5 195515 164043.5 203663.5 48 hrs. 159393.5 188441.5 193650.5 165054 201596.5 72 hrs. 160155.5 191011.5 194922 163151 202989 96 hrs. 161090.5 190499.5 194417 161374.5 101173.5 112 hrs. 159825.5 197281 196546.5 164662 204844

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Figure 2: Mean Oxygen Levels vs. Time

Table 2 and Figure 2 show the mean oxygen levels for the cupcakes baked with

sugar, Stevia, Sweet N’ Low, and Splenda, including a control. The highest mean was

the sugar cake with a mean of 156.360, and the lowest was the Sweet N’ Low cake with

a mean of -767.568. The lowest range was the Stevia cake with a range of 3.698; the

highest was the Sweet N’ Low cake with a range of 1482.073. The mode, however, was

not applicable. The Sweet N’ Low cake had the highest standard deviation out of the

other independent variables; the standard deviation of the Sweet N’ Low cakes was

1047.984. The Stevia cake had the lowest standard deviation which was 2.615. The

control oxygen levels started off lower than the other independent variables. The Splenda

cake dropped around hour 96 and the Sweet N’ Low cake dropped around hour 24. The

control had an increase at around 24 hours. The Sugar and Stevia cakes, however, stayed

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constant throughout the testing period. There was a statistically significant difference

(p>0.05) for change in oxygen levels between the container with no cake and the Splenda

cake, and no cake and the Stevia cake. However, there was no statistically significant

difference for change in the oxygen levels for the rest of the independent variables tested.

The data above failed to reject the null hypothesis that if the mini pound cake is made

with a sugar substitute then it will not take longer to decompose compared to the cake

made with refined sugar, and the data did not support the hypothesis.

Table 3: Mean of Temperature over 5 days Temperature (˚F)

Nothing Sugar Stevia Sweet N’ Low

Splenda

Day 1 60 62 63.5 61 60 Day 2 60.5 62 64 61.5 60 Day 3 59.5 62 64 61 59.5 Day 4 61 63.5 63.5 63 60.5 Day 5 60 63 63 62.5 63

Figure 3: Mean of Temperature vs. Time

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Table 3 and Figure 3 show the effect of the sugar and sugar substitutes on the

mean temperature levels of cupcakes. The highest mean was the Splenda cake at 0.6, and

the lowest mean was the Stevia cake at -0.1. The mode was not applicable. The highest

range was the Splenda cake at 1.2, and the lowest range was the control at 0. The

Splenda cake had the highest median at 0.6, and the control had the lowest median at 0.

The highest standard deviation was the Splenda cake at 0.848, and the lowest standard

deviation was the control at 0. The temperature was tested once every day at

approximately 1 o’clock pm. The container with no cake and the Splenda cake had the

same starting temperature. The Stevia and Splenda cakes had the same ending

temperature. The Sugar, Sweet N’ Low, the control, and Splenda cakes had a decrease

on day 3. The Splenda cake , however, continued increasing, unlike the other sugar

substitutes that went up at day 4 and back down on day 5. There was no statistically

significant difference for change in the temperature levels between any of the variables

tested.

VI. Conclusion

The purpose of this experiment is to determine the effect of Stevia, Sweet N’

Low, Splenda, and sugar on the shelf life of a cupcake. Major findings were that overall

there were no drastic drops in comparison to the entire experiment; however, for some

substitutes there were a lot of sporadic changes in both carbon dioxide and oxygen levels.

The temperature levels were approximately consistent because the location of the

cupcakes never changed. They were housed in a very controlled environment, as

compared to someone’s house. In a house there would many factors that could possibly

change the results, including temperature changes, sunlight exposure, and number of

people coming in contact with the cupcake. It was hypothesized that if the cupcake is

made with a sugar substitute then it will take longer to decompose compared to the cake

made with refined sugar. The data collected shows that the hypothesis was not supported.

The sugar has a lower decomposing rate, in comparison to the sugar substitutes. Previous

studies by Gelinas, Roy, and Guillet show that the synthetic cocoa stalled the

decomposition rate. Our data supports their findings. The hypothesis was chosen because

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it was thought that the synthetic substitutes would last longer because they are artificial.

The limitations for this study of shelf life were the technology issues, which prevented

the researchers from not having sufficient time for the proper amount of trials. From a

scientific standpoint, it would have been better to extend the trials so the mold collected

on the cupcakes could be tested as well. Also, there was not enough technology like the

ones found in food chemistry labs that adequately measure shelf life parameters. There

was only access to five Biochambers and five sensors of each type. For further studies, it

is recommended that the trials be extended and performed more times, so more

information and data could be collected. Also, the amount of microorganisms that grow

on each mini pound cake could be measured over time. Shelf life is a big determining

factor for big grocery store chains; this experiment could help these large companies

decide whether or not a cake could be safe for the customer to consume.

VII. Acknowledgements

We would like to thank Mr. Bill Cherry for helping us with all of our technology

problems; our parents, for providing transportation and support; Heathwood Hall

Episcopal School, for providing funds and a place to work; and last but not least, Mrs.

Lisa Norman, our honors biology teacher, without her support and patience, this project

wouldn’t have happened.

VIII. Works Cited

Dunn J. Way of Shelf Life. Food Manufacture 2010 May; 33-34. Graham, Ian. "Chapter 5: Packaging and Preserving." Food Technology.

London: Evans Brothers Limited, 2008. 48. Print. Kaplan, Aaron, and Leonora Reinhold. "CO2 CONCENTRATING

MECHANISMS IN PHOTOSYNTHETIC MICROORGANISMS." Annual Review of Plant Physiology and Plant Molecular Biology 50 (1999): 539-570. Print.

Kilcast, David, and Persis Subramaniam. The Stability and Shelf Life of Food. Abington, Cambridge: Woodhead Publishing Limited, 2010. Print.

Malovany D. Live Long-g-g and Prosper. Snack Food & Wholesale Bakery 2002 Mar.; 1-3.

Reid, Daniel. "Sugar." Which colon cleansing gives Best Results? The one where someone personally guides you! . HPS-Online, n.d. Web. 10 Oct. 2010. <http://www.hps-online.com/foodprof1.htm>.

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Sarquis E.D., Mickey. "Preservatives." Chemical Cuisine Spring 2001: 1. Print. Shultz, Martin. "Month-long bread? Getting the basic seven-day extended-shelf

life bread formula right is hard enough. Moving to 30 days can make any baker lie awake at night for a number of reasons. (Ingredient R&D)." Snack Food & Wholesale Bakery 1 May 2003. Print.

Taoukis, Petros, and Theodore Labuza. "Integrative Concepts." Food Chemistry Mar. 1996: 88. Print.

"Technical brief, measuring carbon monoxide." Western Area Power Administration. Energy Services, n.d. Web. 10 Oct. 2010. <http://www.wapa.gov/es/pubs Terao, Tomio, and Shu Miura. "Influence of free-air CO2 enrichment (FACE) on the eating quality of rice." Journal of the Science of Food and Agriculture 85.11 (2005): 1861–1868. Print Wilson L R. Easy Dessert With 5 Ingredients or Less. (TX): Cookbook Resources LLC.; 2003. 1 p.