TEAM ABSOLUTE
Allison Witt, Matt Born, Subir Shah, Aiva Mesi
LBS 145L
02/26/03
ABSTRACT
Various tests were conducted on two mainstream beers, Bud Light and Killian’s, in order to compare the components of each solution. Both beers vary in color, taste, and smell, which from our tests seem to account for the different organic macromolecule composition. We hypothesize that Killian’s and Bud Light will vary in the type carbohydrates present. By performing Benedict’s, Barfoed’s, Selivanoff’s, Bial’s, and the Iodine test, we were able to determine that both beers contained disaccharides with pentose-furanose rings. Killian’s, however, contained reducing sugars, while Bud Light did not. To analyze how the beers affected the photosynthetic pigmentation in plants, we fed Wisconsin Fast Plants the two types of beers over a two-week span and performed paper chromatography and absorption spectrum tests. Our hypothesis for the photosynthesis lab was that the plants fed with Killian’s would have less variance of pigments and will have a smaller absorption spectrum. From these tests, we concluded that the Killian’s plants had a wider absorption spectrum than Bud Light. Our group also tested each beer for the presence of amylase and PPO, finding that both beers contained amylase but neither contained PPO. Thus, we performed another experiment using time elapsed photos and the spectrophotometer to see which beer could catalyze starch the fastest. We found that Killian’s had a higher concentration of the enzyme because it was able to breakdown the starch faster than the Bud Light samples. This experiment supported our initial hypothesis that Killian‘s would have more of the enzyme present.
FIGURE 26. Photograph of three test tubes used to find out which beer has more Amylase present. The blank tube on the left contains only 5000 ul of Killian’s. Tube C contains 5000 ul of Killian’s and 125 ul of Iodine and Tube D contains 5000 ul of Killian’s, 125 ul of Iodine, and 1000 ul of starch. Photograph taken 8 minutes and 20 seconds after starch had been added to tube D.
DISCUSSION
Many experiments were conducted to support our initial hypothesis that dark and light beers should have different carbohydrate composition and produce different absorption spectrums in Brassica rapa, and that Killian‘s will have more amylase present. The presence of carbohydrates and enzymes, and differences in pigments were the tests conducted to prove our hypothesis. The two beers should produce different results in the carbohydrate tests, the beers should be similar in the enzyme composition and concentration, but the photosynthesis tests should not show similar results because of the different pigmentation in the beers.
We expected to see variance in the carbohydrates present. Benedict’s test supported our hypothesis. This particular carbohydrate test indicated whether a free aldehyde or a ketone group was present. For Killian’s, Benedict’s test produced a yellow precipitate and a dark green color (Figure 4). This precipitate predicts the presence of a reducing sugar, or a free aldehyde or ketone group. For Bud Light, this Benedict’s solution produced a green color, but no precipitate. This test indicates that there are no reducing sugars in Bud Light. Killian’s, on the other hand did contain reducing sugars. This experiment verified our hypothesis. All of the other tests produced similar results. Barfoed’s test, which tested for the presence of monosaccharides or di/polysaccharides, produced no change (Figure 6). If a rusty brown precipitate was present, then it would indicate that monosaccharides are in solution. Since all tests resulted in no brown precipitate and the solution remained a bright blue, neither beers contain monosaccharides. In Selivanoff’s test, testing for a ketose or an aldose, both beers appeared to have the same results (Figure 8). When there is a red color change in the resulting solution, the sugars present are ketoses. Because both beers changed from a relatively clear solution to a red color we knew that the sugars in the beers were ketoses and because the color change occurred in around a minute the ketoses are not monosaccharides. Bial’s test, which checks for the presence of a furanose ring, initially started with a yellow solution produced an olive green color after the test was performed. This result supports the presence of a pentose-furanose ring (Figure 7). The Iodine test was the final test performed in a series of five. When iodine was added to Bud Light and Killian’s, the solution turned yellow. If a bluish-black color resulted this would indicate starch is present. Therefore the tests came back negative for both types of beer, meaning that starch is not present in both beers (Figure 5). These tests conclude that both beers have similar carbohydrate composition, but differ in the presence of reducing sugars. This finding correlates with our initial hypothesis, that the sugars in the beers vary. We were also able to make assumptions on the carbohydrates present in these beers. Our tests show that the sugar may be a disaccharide with one of the monosaccharides being a pentose-furanose ring and the other may be one of many monosaccharides, possibly maltose. This data correlates with our research and hypothesis. These beers are composed of the same basic ingredients: barley, water, hops, and yeast, therefore, it is not surprising that the carbohydrates present are relatively similar (Jackson, 1988).
According to our research on the brewing process, amylase is added in several steps including “malting” of germinating barley and is important in removing starch hazes to produce clear, bright beer (Anonymous, 2001). Because we found this information on an internet site, our team wanted to analyze each beer and determine whether the site was accurate on its information. We also wanted to see if the enzyme was destroyed during the brewing process. Because starch is the substrate for amylase we added this to each beer and tested the beer‘s ability to catalyze the substrate. It was found that both beers contained active amylase. This was supported by the ability of both liquids to catalyze starch. Killian’s, however, was able to catalyze the same amount of starch at a much faster rate (Figure 12 and 13, Table 3). This supports the idea that Killian’s contains more amylase than Bud Light. Another test that was conducted was to see if each type of beer contained PPO. If there was a presence of PPO in either beer, the resulting solution would be darker than the starting solution. This darkness would show that PPO was present because when the enzyme catalyzes catechol it produces o-benzoquinone, which is a brown color. However, since our resulting solutions did not change color, our experiment supports the idea that PPO is not present in beer (Figure 11). Again, these enzyme tests helped support our initial hypothesis that both beers have similar enzyme composition.
The last tests we conducted were used to determine the presence of photosynthetic pigments in Brassica rapa plants. We had three sets of plants 1) Plants fed with Bud Light 2) Plants fed with Killian’s and 3) Plants fed with water. We predicted that the two types of beer would cause differences in photosynthetic pigmentation of Wisconsin Fast Plants because of their different colors. Our initial hypothesis was that the plants that were fed with Bud Light would have a wider absorption spectrum than that of the plants that were fed Killian’s. We thought this because Bud Light had a lighter color and assumed would absorb more light. Our experiment, on the other hand, disagreed with our hypothesis and showed that Killian’s had the wider absorption spectrum (Table 2, Figure 7). The paper chromatography lab was used to identify the presence of pigments: carotene, chlorophyll a, chlorophyll b, and xanthophylls. All three types of plants showed the same paper chromatography results (Figure 10). The beers did not affect photosynthetic pigmentation.
Our results only partially supported our initial hypothesis. Many aspects in our experiment could have affected our results. If we had more time, we could have done more replications to ensure that our results were accurate. Secondly, there could have been more variables to test if we had conducted more research. Also, there is always the possibility of human error in an experiment. We may have fed the Bud Light plants more beer than the Killian’s from which they could absorb more water. We may have also observed incorrect responses to the sugar and enzyme tests. Professionally speaking, to build a solid foundation on our results, many more replications of our experiment would be needed to prove our results correct.
Various tests were conducted on two mainstream beers, Bud Light and Killian’s, in order to compare the components of each solution. Both beers vary in color, taste, and smell, which from our tests seem to account for the different organic macromolecule composition. We hypothesize that Killian’s and Bud Light will vary in the type carbohydrates present. By performing Benedict’s, Barfoed’s, Selivanoff’s, Bial’s, and the Iodine test, we were able to determine that both beers contained disaccharides with pentose-furanose rings. Killian’s, however, contained reducing sugars, while Bud Light did not. To analyze how the beers affected the photosynthetic pigmentation in plants, we fed Wisconsin Fast Plants the two types of beers over a two-week span and performed paper chromatography and absorption spectrum tests. Our hypothesis for the photosynthesis lab was that the plants fed with Killian’s would have less variance of pigments and will have a smaller absorption spectrum. From these tests, we concluded that the Killian’s plants had a wider absorption spectrum than Bud Light. Our group also tested each beer for the presence of amylase and PPO, finding that both beers contained amylase but neither contained PPO. Thus, we performed another experiment using time elapsed photos and the spectrophotometer to see which beer could catalyze starch the fastest. We found that Killian’s had a higher concentration of the enzyme because it was able to breakdown the starch faster than the Bud Light samples. This experiment supported our initial hypothesis that Killian‘s would have more of the enzyme present.
FIGURE 26. Photograph of three test tubes used to find out which beer has more Amylase present. The blank tube on the left contains only 5000 ul of Killian’s. Tube C contains 5000 ul of Killian’s and 125 ul of Iodine and Tube D contains 5000 ul of Killian’s, 125 ul of Iodine, and 1000 ul of starch. Photograph taken 8 minutes and 20 seconds after starch had been added to tube D.
DISCUSSION
Many experiments were conducted to support our initial hypothesis that dark and light beers should have different carbohydrate composition and produce different absorption spectrums in Brassica rapa, and that Killian‘s will have more amylase present. The presence of carbohydrates and enzymes, and differences in pigments were the tests conducted to prove our hypothesis. The two beers should produce different results in the carbohydrate tests, the beers should be similar in the enzyme composition and concentration, but the photosynthesis tests should not show similar results because of the different pigmentation in the beers.
We expected to see variance in the carbohydrates present. Benedict’s test supported our hypothesis. This particular carbohydrate test indicated whether a free aldehyde or a ketone group was present. For Killian’s, Benedict’s test produced a yellow precipitate and a dark green color (Figure 4). This precipitate predicts the presence of a reducing sugar, or a free aldehyde or ketone group. For Bud Light, this Benedict’s solution produced a green color, but no precipitate. This test indicates that there are no reducing sugars in Bud Light. Killian’s, on the other hand did contain reducing sugars. This experiment verified our hypothesis. All of the other tests produced similar results. Barfoed’s test, which tested for the presence of monosaccharides or di/polysaccharides, produced no change (Figure 6). If a rusty brown precipitate was present, then it would indicate that monosaccharides are in solution. Since all tests resulted in no brown precipitate and the solution remained a bright blue, neither beers contain monosaccharides. In Selivanoff’s test, testing for a ketose or an aldose, both beers appeared to have the same results (Figure 8). When there is a red color change in the resulting solution, the sugars present are ketoses. Because both beers changed from a relatively clear solution to a red color we knew that the sugars in the beers were ketoses and because the color change occurred in around a minute the ketoses are not monosaccharides. Bial’s test, which checks for the presence of a furanose ring, initially started with a yellow solution produced an olive green color after the test was performed. This result supports the presence of a pentose-furanose ring (Figure 7). The Iodine test was the final test performed in a series of five. When iodine was added to Bud Light and Killian’s, the solution turned yellow. If a bluish-black color resulted this would indicate starch is present. Therefore the tests came back negative for both types of beer, meaning that starch is not present in both beers (Figure 5). These tests conclude that both beers have similar carbohydrate composition, but differ in the presence of reducing sugars. This finding correlates with our initial hypothesis, that the sugars in the beers vary. We were also able to make assumptions on the carbohydrates present in these beers. Our tests show that the sugar may be a disaccharide with one of the monosaccharides being a pentose-furanose ring and the other may be one of many monosaccharides, possibly maltose. This data correlates with our research and hypothesis. These beers are composed of the same basic ingredients: barley, water, hops, and yeast, therefore, it is not surprising that the carbohydrates present are relatively similar (Jackson, 1988).
According to our research on the brewing process, amylase is added in several steps including “malting” of germinating barley and is important in removing starch hazes to produce clear, bright beer (Anonymous, 2001). Because we found this information on an internet site, our team wanted to analyze each beer and determine whether the site was accurate on its information. We also wanted to see if the enzyme was destroyed during the brewing process. Because starch is the substrate for amylase we added this to each beer and tested the beer‘s ability to catalyze the substrate. It was found that both beers contained active amylase. This was supported by the ability of both liquids to catalyze starch. Killian’s, however, was able to catalyze the same amount of starch at a much faster rate (Figure 12 and 13, Table 3). This supports the idea that Killian’s contains more amylase than Bud Light. Another test that was conducted was to see if each type of beer contained PPO. If there was a presence of PPO in either beer, the resulting solution would be darker than the starting solution. This darkness would show that PPO was present because when the enzyme catalyzes catechol it produces o-benzoquinone, which is a brown color. However, since our resulting solutions did not change color, our experiment supports the idea that PPO is not present in beer (Figure 11). Again, these enzyme tests helped support our initial hypothesis that both beers have similar enzyme composition.
The last tests we conducted were used to determine the presence of photosynthetic pigments in Brassica rapa plants. We had three sets of plants 1) Plants fed with Bud Light 2) Plants fed with Killian’s and 3) Plants fed with water. We predicted that the two types of beer would cause differences in photosynthetic pigmentation of Wisconsin Fast Plants because of their different colors. Our initial hypothesis was that the plants that were fed with Bud Light would have a wider absorption spectrum than that of the plants that were fed Killian’s. We thought this because Bud Light had a lighter color and assumed would absorb more light. Our experiment, on the other hand, disagreed with our hypothesis and showed that Killian’s had the wider absorption spectrum (Table 2, Figure 7). The paper chromatography lab was used to identify the presence of pigments: carotene, chlorophyll a, chlorophyll b, and xanthophylls. All three types of plants showed the same paper chromatography results (Figure 10). The beers did not affect photosynthetic pigmentation.
Our results only partially supported our initial hypothesis. Many aspects in our experiment could have affected our results. If we had more time, we could have done more replications to ensure that our results were accurate. Secondly, there could have been more variables to test if we had conducted more research. Also, there is always the possibility of human error in an experiment. We may have fed the Bud Light plants more beer than the Killian’s from which they could absorb more water. We may have also observed incorrect responses to the sugar and enzyme tests. Professionally speaking, to build a solid foundation on our results, many more replications of our experiment would be needed to prove our results correct.