Comparison of carbohydrate, pigment, and protein content in the herbs Rosemary, Sage and Oregano.

By:

Blue Bees

Maggi Lewis, David Ramsey and Jennifer Harsch

LBS 145: Molecular Biology

Tuesday 7-10pm

James and Brent

Abstract

We investigated what the difference in sugars, protein and pigment content is of three different common household herbs: Rosemary (Rosmarinus officinalis), Oregano, (Origanum Vulgare), and Sage (Salvia Apiana).Ê We investigated how three types of herbs vary in content of reducing sugars, presence of starch, action and absorption spectrums, and protein content.Ê In addition to comparing fresh rosemary, oregano, and sage, we will compare fresh rosemary to dried rosemary. We used Benedictâs and Barfoedâs tests for reducing sugars, as well as the Iodine test for starch.Ê In week two, we created and compared the action and paper chromatography for the specified herbs.Ê In week three, we created a standard curve for protein concentration, then test our herbsâ protein content. The Benedictâs test showed all herbs but the dry rosemary contained monosaccharides.Ê Dry Rosemary and oregano showed positive results in Barfoeds while wet rosemary and sage showed negative.Ê The action spectrum yielded fairly close results, with the exception of the dry rosemary, as well as the paper chromatography.Ê The Bradford Assay showed fairly close results as well.

Discussion

Since the portions of the plants we tested during these experiments were the leaves and not the roots, we believed correctly that there would be no deposits of starch revealed in the Iodine test. The reducing sugar tests (Benedictâs and Barfoedâs) was slightly disappointing, as the Benedictâs seemed to show no traces of a reducing sugar (free aldehyde or ketone groups) while the Barfoed test showed positive results for monosaccharides.Ê All of the herbs showed a positive result for Barfoedâs with wet oregano having an exceptionally high concentration comparatively to the other herbs.Ê However in the Benedictâs test there may have been reducing sugars.Ê Due to the color of the solutions before the test was run, a possible color change was hard to decipher.Ê The original color of the solution was a dark green, making a distinct red precipitate hard to recognize.Ê We had expected that the two tests would have a strong correlation between the positives of one another.

ÊÊÊÊÊÊÊÊÊÊÊ The pigment test yielded no great surprise, as the dried out leaves of a plant would have little to no pigment capable of reacting with solution.Ê The second pigment xanthophyll in the Sage where our other samples had only chlorophyll α was interesting mainly because we have never seen Sage as anything except green.Ê On the reverse side, the lack of any visible second pigment in Oregano, which has a discernable yellow tint at certain stages of growth, was disappointing.Ê Had we anticipated these results a separate sample of oregano with the yellow tinted leaves would have been run in addition to the predominantly green leaf version.

Action Spectrum produced some interesting results.Ê It seemed to indicate that some of the leaves of the herbs function more efficiently in a white light spectrum.Ê According to our data dry rosemary was able to go through the most photosynthesis.Ê This seems to be a source of error, due to the fact that dry rosemary is dried and the least amount of photosynthesis should be in a dried substance, in comparing to wet substances that are fresh.Ê A test such as this should be run more than two or three times and under far more controlled conditions than what was available in this lab.Ê

During the Bradford Assay we discovered Sage and Rosemary to have nearly the same concentration of protein.Ê Fresh Oregano had an overwhelmingly higher absorbance when compared to the other two samples.Ê When we look back to the paper chromatography the sage showed the most pigments.Ê Since the sage has more pigments it is able to capture more wavelengths of light and thus more energy.Ê There may have been sources of error that caused sage to drop beneath rosemary in the second trial of the Bradford Assay.Ê As the results showed there was only one data point that dropped beneath rosemary. If more time was given to run more test, this source of error may have been corrected.Ê

Overall this lab answered the questions we laid out in the beginning as well as reinforced some of our old beliefs, which is always a relief in science.Ê The only drawbacks for these experiments would be the lack of time to perform the amount of repetitions necessary to average our results, as well as a consistent solution mixture from which to run our tests.Ê These problems are nothing new to scientists, and are something we all must strive to work around as best we can.

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Figure 3: Paper Chromatography results

From left to right the figures shows the results of the positive and negative controls, then the Wet Rosemary, then the Sage, then the Oregano and last the Dry Rosemary.Ê The pictures show which had more pigments and which had none.Ê The wet rosemary and the oregano showed pigments up the to xanthophyll line even though you cannot see it in the photograph.