Monday, March 12, 2012

Nerding Out: Essential Oils

Toddler Melissa doing "homework."
I used to like doing homework. A lot. It was satisfying to come home from a long day of school and practice what I had learned. Perhaps I would fill in the blanks, or circle the one thing that was not like the other things, or, in later years, solve for x. I didn't always get the right answer (especially when it came to finding x), but I was grateful that there was a right answer, and that I could tune out all the surrounding chaos at home and try to find it. 

Fast forward to today. Here I am, a much older nerd, about to isolate the essence of cinnamon by extraction with methylene chloride. See how laughter and joy is just pouring out of me? 

Wouldn't this make a great passport photo?
In fact, isolating natural products is cool, if a little tricky. There's a real art to distillation technique. It made me want to do it at home without using toxic chemicals. If you decide to make your own essential oil don't ingest it. That would be gross. 

Here's how we did it in the lab:

1) Take a cinnamon stick and break it up into smaller pieces. The pieces were placed in a round bottom flask with 4 mls of water and a boiling stone.

Use stick, not powdered cinnamon for better results.
 2)Attach a still and condenser to the flask, heat it in a sand bath at 150-160 degrees C. 

Hickman still and air condenser.

3)A milky distillate forms in the still. This was removed using a syringe and placed in a centrifuge tube.

4) The organic layer of essence was extracted from water in the distillate using methylene chloride.

Milky layer of plant matter.

5)We evaporated the methylene chloride over gentle heat, and analyzed the product. 

Yay a graph!
Essential oils smell great and distilling them has been a human endeavor since the early days of alchemy. I find it fascinating that the way a molecule is shaped determines how it tastes or what odor it has. 

Have you ever chewed spearmint gum for a really long time and noticed it eventually tastes kind of like rye bread? Carvone is the molecule responsible. In one form it is the flavor of spearmint, but its mirror image is the flavor of caraway seeds. 

Somehow I manage to out-nerd the graph.

There are so many flavors to experiment with. If you don't have a still (who does?) you can use jojoba oil, add some crushed flower petals, or the rind of an orange, or fresh mint leaves. Let the plant material steep in the oil for a day or two in a closed container. Strain the oil and repeat until you get your desired pungency. 


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