"Worldwide" v. "Designer Whey":

Sugar, pigment, and protein tests find differences only in protein concentration

The Green Team

Nina Flores 

Lauren Simpson 

Lisa Teverbaugh 

Colleen Weiler


Abstract (By Nina Flores Revised by Colleen Weiler Final Revisions by Lauren Simpson)

Throughout this experiment, two different brand protein bars, “Worldwide” which advertised “improved taste and “Designer Whey” which advertised a “candy-like” taste, were tested for content.  The sugar types, photosynthetic pigments, and protein concentration were analyzed to reason the difference between brands.  We predicted that the “Designer Whey” bar would have more fructose, a sweeter sugar, than the “Worldwide” bar to create the “candy-like” taste.  We also predicted that the “Worldwide” bar would have more photosynthetic pigments than the “Designer Whey” bar because a “candy-like” taste seems more processed and sugary, which would leech out the photosynthetic enzymes in the bar and leave less room for natural photosynthetic material.  For our protein test, we predicted the “Worldwide” bar would have a higher concentration for similar reasons.  The “candy-like” taste in the “Designer Whey” bar would take precedence over protein concentration.  To evaluate the different types of sugars in the bars, the five tests we did were Barfoed’s, Bial’s, Selivanoff’s, Iodine, and Benedict’s.  From these we found similar results for the bars.  They both contained sugars that were non-reducing di- or polysaccharides.  They contained ketoses, furanoses and starch.  This did not support our hypothesis.  In our paper chromatography test to identify what types of photosynthetic pigments were present, both bars showed no photosynthetic pigments.  To determine the protein concentration of the bars, we performed the Bradford Assay.  The “Worldwide” bar was found to have a lower protein concentration than the “Designer Whey” bar, which suggests that our predictions were incorrect.



Our Worldwide protein bar solution


Discussion (Colleen Weiler, Revision 1: Lisa Teverbaugh, Revision 2: Nina Flores)
    In today’s society there is a general obsession with weight loss, especially with quick and easy weight loss, so much so that a wide variety of fad diets and foods to help you drop pounds quickly have been introduced within the last decade.  While a lot of diets are surrounded by hype and media blitz, along with “testimonials” from actual clients, there are some that argue that these diets may actually adversely affect your health in the long run.  We looked at some studies that argue that high-protein diets such as the Atkins Diet may cause more health problems over time, such as depleting muscle strength, increasing cholesterol (Anderson & Jenkins, 2000) or causing kidney stones or osteoporosis (Gilbert, 2000).  Proponents of high-protein diets argue that eating a lot of carbohydrates is the real cause of weight gain, and that high intake of sugar could result in an increased risk of pancreatic cancer (Michaud & Giovannucci, 2002).  
In this experiment, we decided to test two different protein bars to see if they really offered more of a nutritional benefit and compare them to see which was healthier overall.  We hypothesized that the Designer Whey bar, which was advertised as having a “candy-like taste,” would contain fructose, a sweeter tasting sugar, than the Worldwide bar, a bar advertised simply as having an “improved taste” and would therefore have sucrose as its sugar component.  We also predicted that the Designer Whey bar would contain fewer pigments and therefore less organic material and have a lower protein concentration than the Worldwide bar, because it would have a higher concentration of sugar.  Our results for the pigment identification refuted our hypothesis because no pigments appeared on our paper chromatography for all three trials for each bar, so it could not be determined if the two protein bars contain different amounts of photosynthetic material. For the sugar tests, the results showed no difference for the sugars in the bars, and did not support our hypothesis.  In the Bradford Assay, testing for protein concentration, our results were opposite our predictions.  We thought that the Worldwide bar would have a higher concentration of proteins because it has more grams.  However, the Designer Whey bar actually had a higher concentration of proteins.

Sugar Analysis
The results of the sugar tests showed that the two bars contained similar types of sugar, and since we had no tests to determine the quantity of sugars in the bars or exactly what sugars they contained, we could not tell exactly what was in the bars.  As Table 1 shows, the sugar tests for the bars show no difference, except in the Iodine test, results that do not support our hypothesis.  We ran three trials for each bar solution and it still showed no sugar difference. This is could be due to the processing the bars underwent, as well the other ingredients contained in the bars, because we not working with pure sugar solutions, as in the control sugar tests.
Benedict’s test determines if the carbohydrate contains a free aldehyde or ketone group.  If there is a free group, copper is reduced in the reaction and a red precipitate forms in the solution.  Both bar solutions in all three trials formed a green precipitate, showing that they both have a free aldehyde or ketone.  While the control shows a red precipitate, we were not testing pure sugar, so other materials in the bars could have altered the color of the precipitate.  
Barfoed’s test distinguishes between monosaccharides and di- or poly- saccharides and will change the color of the solution to a rusty brownish-red if monosaccharides are present.  Neither of the bars’ solutions changed color, indicating di- or polysaccharides.  
In Selivanoff’s test, which distinguishes between ketoses and aldoses, the reaction will occur in less than one minute if the solution contains ketoses.  Both bars turned red in under one minute, so they both contain ketoses.  Fructose is a ketose and sucrose is an aldose, so this test was vital in determining the different sugars in the two bars.  The Designer Whey bar, which is the candy-like bar, turned a darker red at the end, although the reaction occurred more slowly than the Worldwide bar.  This could suggest that the Designer Whey bar contains both fructose and sucrose, with more fructose, but the test was inconclusive and we cannot determine if the bar does contain more fructose.  
Bial’s test shows the different five-membered rings in the sugars; if the solution turns green, pentose furanoses are present, if olive/brown, hexose furanoses are present.  Both solutions turned olive for all trials, indicating hexose furanoses.  
The final sugar test we performed, the Iodine test, tested for the presence of starch by turning the solution bluish black.  Here we did see some differences in the results.  The Worldwide solution turned a dark green, indicating starch, and the Designer Whey bar a light brown, indicating that no starch was present.  The dark green can be interpreted in the same way as the dark blue for our control Iodine test, since other factors in the bar may influence the color and color changes.
Both bars contain multiple types of sugar, so their overall nutrition advantages are lessened.  Sugar provides a quick boost of energy that can quickly wear off because it is absorbed faster than protein, which provides prolonged energy because it is absorbed more slowly.  The results of these sugar tests did not support our hypothesis because they did not show any significant differences between what sugars the bars contained.

Photosynthesis Analysis
In the Paper Chromatography pigment identification test, which tests for different types of pigments in organic material, we predicted that the candy-like Designer Whey bar would contain fewer pigments and therefore less organic material because organic material usually degrades the taste of foods unless it is artificially sweetened, as we believed this bar would be.  Specifically, we predicted the Designer Whey bar would contain only chlorophyll-b and chlorophyll-a, because all plant material must contain at least chlorophyll.  The Worldwide bar, in contrast, would have more organic material and would contain chlorophyll-a, chlorophyll-b, xanthophyll and carotene.  The results of our paper chromatography show that neither bar contains any photosynthetic material, results that do not support our hypothesis. The amount of processing and shelf time may have degraded any organic material that was originally present in the two bars.

Enzyme Analysis
For the enzymes, we predicted that the two bars would have different concentrations of proteins, although the ingredients on the bars showed that the two contained the same amount of proteins in grams.  We believed that the different types of sugar may affect the total concentration of proteins in the bars, but since our sugar tests did not show any differences, we were unable to make that connection.
The Bradford Assay tests for the total protein concentration in a solution.  Our results showed that the Worldwide bar had a lower concentration of protein enzymes, despite having a higher amount in grams. We used a calculation from the trendline made from our graph of Absorbency vs. BSA concentration.  These calculations found that the Designer Whey bar had concentrations of 1.0, 1.3, and 1.18.  The Worldwide bar had concentrations of 0.98 and 0.94.  These results are opposite of our hypothesis, and do not support it. The Designer Whey bar had higher concentrations of protein, possibly because the bar was not homogeneous throughout.  We may have tested a piece with a higher concentration of protein. The Designer Whey bar was made mostly of fruit and so could have higher concentrations of protein in the middle, while the Worldwide bar may have had its protein spread out, as it was a mixture of chocolate and fruit.

Interpretations
 Protein is an important source of energy for our body.  It is mainly digested in the stomach and absorbed through the small intestine as amino acids, and go into our bloodstream to provide energy.  For this reason, one would assume that the Worldwide bar is actually healthier than the Designer Whey because it has a higher mass of proteins, but a lower concentration that is more spread out, and absorbed into the blood stream at a slower rate and provides more energy.  Many fad diets are focused around high-protein intake, despite evidence that the long-term effects of high-protein diets such as The Atkins Diet and The Zone can actually be unhealthy.  While high protein diets help people to lose weight quickly, most of the weight lost is water weight.  The increased intake of fats as protein reduces the amount of water, since 1g of fat can only store 0.5g of water, compared to the 2-3g of water that 1g of glycogen, a carbohydrate, can store.  The high-fat, high-protein diets will, over time, deplete muscle and increase cholesterol in the body (Anderson & Jenkins, 2000).  Recall that water is an important part of the human circulatory system, and many functions in our body are dependent upon our water intake (Freeman, 2002).  The Designer Whey bar contains a higher concentration of protein, and a large amount of carbohydrates in the form of sugar, balancing out the long-term nutritional values of the bar.  Since carbohydrates begin to break down in the mouth with salivary amylase, this bar will provide more of an energy boost (Freeman, 2002).  However, carbohydrates that are not burned as energy are stored and can lead to weight gain.  The Worldwide bar will help in quick weight loss because it contains more proteins in grams, but may be detrimental to the body in the future.  Both bars contain enough protein to give a powerful energy boost, and should be eaten in place of a meal, instead of as an addition to one (Anonymous, 2000).  
    Results from our experiment may be affected by differences in the bars.  They are not the same brand, so we do not know if they are made the same way or contain equal amounts of all ingredients besides the sugars.  While they are both fruit-flavored, they contain different fruits, which can affect the carbohydrate and fiber contents of the bars, the pigmentation of the bars and their photosynthetic ability. Designer Whey was mostly fruit in the center with a chocolate coating, and the Worldwide was a mixture of chocolate and fruit throughout.  We chose bars that had very similar fruit filling to try and avoid this problem as much as possible.  However, it is hard to know if the bars still contained any natural elements since they had been processed and packaged.  The different types of sugar may also affect the way the proteins are broken down, which is something we were unable to determine in the lab.  Performing the experiment, we had trouble creating the 1% solutions of the bars and with breaking down the bars for the Pigment Identification.  While in storage, the solutions separated, and though they were thoroughly mixed before use, error could still occur as a result.  We created an approximate 4% solution of the bars, but other elements in the bar may affect the sugar tests.  Since the solutions were colored, it was also difficult to see the color changes and precipitates formed in the solutions.  For example, the solution we made for the Designer Whey bar was brown, which affected the color of the precipitate formed in Benedict’s test. This could be fixed by using a lower concentrated bar solution (2% vs. 4%) to see the color change results more clearly.
We were also unable to determine the quantitative amount of sugar in each bar, which would be helpful in determining the true differences between the bars, especially in the sugar tests.  A more extensive Benedict’s test, in which the solutions were placed in a spectrometer to determine exactly how red the solutions were, would tell us which bar contained more ketoses.  Quantitative tests could determine the amount of grams of sugar in the bars.  A graphed curve with the results of solutions containing known amounts of chlorophyll could help to determine how much chlorophyll could be extracted in a different photosynthesis test, the Absorption Spectrum. For Bradford Assay, higher concentrations of BSA (up to 100) could provide a better graphical representation for clearer understanding of the amounts of protein found. If we had access to quantitative tests to use for our protein bars, we might have had more accurate, providing us with results that could more conclusively relate to our hypothesis.  As for fad diets and their true health benefits, we leave it to the next experimenters to determine what they really are.