MadSci Network: Botany |
Complete question: I was testing transpiration on Coleus plants by coating the top and bottom of the leaves with mayonnaise along with other substances. The pigments in the leaves of that plant changed color. The yellow disappeared and the green part in the leaves grew darker after the mayonnaise was applied. It was within about 6 hours that the leaves turned. The light purple turned almost to a black and the light green changed into a dark green. I repeated it with another plant, and the same thing happened. Answer: Mayonnaise contains vegetable oil, egg, and vinegar. The vinegar is acid so it is likely that the anthocyanin pigments in the coleus leaf are changing color due to the acid pH. You might try just using vinegar to help confirm that as the cause. The vegetable oil may or may not be needed to solubilize the plant membranes to allow the vinegar to enter. A classic, and very popular, school experiment uses the pH-induced color change of anthocyanins in red cabbage leaves or other plant materials as a pH indicator. To find lots of sites, use a search engine like google.com and search for red cabbage pH. Reference Red Cabbage pH Indicator Red Cabbage
Response:
Re: Does coating a plant's leaves with mayonnaise affect the leaf's pigments? Greetings - Your question was not submitted to the MadSci Network for the following reason: Please provide further specifics. As it stands it would be difficult for us to find an answer to your question. Questions may be resubmitted via http://www.madsci.org/submit.html Hi Jenny - It would help to know the time course of how/when the pigments changed - was it a matter of days, a week, or more? Cheers.. Lynn Bry, Admin MadSci Network _______________________________________________________________ I was testing transpiration on Coleus plants by coating the top and bottom of the leaves with mayonnaise along with other substances. The pigments in the leaves of that plant changed color. The yellow disappeared and the green part in the leaves grew darker after the mayonnaise was applied. ________________________________________________________________ MadSci Network http://www.madsci.org/ webadmin@www.madsci.org
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