Extracting limonene (Orange Oil) from Citrus “zest” using the EssenEx-100®
Orange (and other Citrus) Oil is predominantly composed of the chemical limonene. This compound has many interesting properties as can be learned from internet and other resources. IN particular, it is considered an anti-oxidant as well as a natural cleaning agent. In our case, however, it is also a very good, consistent material easily extracted using the EssenEx-100®. The process to do so is as follows:
- Obtain 3 to 5 oranges. While organic grown oranges usually have more oil, any oranges will be fine. We need about 50 grams of “zest” for one run.
- “Zest” off the orange part of the orange rind. This is the material you need! You may eat the orange, as it doesn’t have very much orange oil inside! While I say “zest”, actually it is easier in my opinion to just use a medium to fine grater and grate off the color portion of the rind. It’s OK if some of the white inner rind is included.
- Using a kitchen or postage scale, weigh out 50 grams of this “zest” and then place it in the EssenEx-100®. I find it easiest to invert an ice core mold, put it over the beaker and shield and then pour the zest directly into the EssenEx-100®. The inverted ice core mold ensures that all the zest only goes in the annular ring around the beaker and shield.
- Assemble the EssenEx-100® as usual for extraction.
- One easy way to get the ice core out of an ice core mold is to pour a bowl of water, then place the ice core mold with the ice frozen inside into the bowl. Rather quickly, the ice will release itself from the inside of the ice core mold and be easy to then affix to the lid of the EssenEx-100®.
- Place the EssenEx-100® into the microwave and run on HIGH for 6 minutes.
- Let it then cool for about 5-6 minutes, either in the Microwave or resting on a “hot pad”. Don’t open the lid just yet!
- After the cooling period, collect the oil.
- Yield should be 1-3 ml of orange oil (limonene). This will show up in the neck of the volumetric flask separator.
The first time I did the Orange oil experiment, I was amazed at the quantity of oil, and hope you feel the same way! I use it often to confirm that my microwave is preforming properly and also if I find some plant material that is giving only a tiny amount of oil, as the orange oil extraction then becomes a control standard to confirm to me that I am running the equipment properly.
The orange oil extraction is also a great method to teach steam distillation (chemistry) to folks.
Lastly, here is a Youtube video that a customer made showing the full process: