Re: How can I measure beta carotene in carrots?

Thank you for your question.

Beta-carotene, which is responsible for the orange color in carrots, is usually measured by first grinding up the carrot, then removing the beta-carotene using a solvent. The solvent (usually hexane) is able to dissolve the beta-carotene and removed it from the carrot because both it and beta-carotene, much like cooking oil, do not mix with water. The extracted beta-carotene is then analyzed by HPLC, or High Performance Liquid Chromatography. Although using HPLC is one of the best ways to analyze for beta-carotene, it is not the only way.

Here is a link to a method for measuring beta-carotene using a spectrophotometer and a centrifuge, equipment which many high school laboratories may have.
http://www.cyanotech. com/pdfs/spirulina/spbul3.pdf

This method was originally designed to measure beta-carotene in dried algae, but you should be able to use it for carrots if you cut them into thin slices and allow them to dry.

You will need to be careful with the solvents (in this case methanol and DMSO) so make sure that you get some help from someone experienced with using them and to always wear gloves, a lab coat, and safety goggles.

Finally, beta-carotene is very light sensitive once it has been extracted from the carrot. For this reason, there are several steps that will be need to done in near-darkness. The best way to do this is to cover all of the windows and use red lights to work by.

Give it a try and good luck to you!