Let's make it

In this section, we would like to introduce an easy method of making essential oils.

We tried compression method with skin of 6 mikans, but we couldn’t extract any oil.

So, we will show you a method of making essential oils that can be easily tried at home.
Essential oil is soluble in alcohol and organic solvents, but not in water. We utilised the solubility of essential oils in alcohol.

Things to prepare ~Using food waste~

We made essential oils using peels of mikan and yuzu.
As it is in winter time, mikan and yuzu are often eaten and used. Our classmates and neighbors helped us to collect peels.

Mikan peal	Yuzu peal

Method ~Report~

Step 1: Drying peals of fruits

The peels of mikan and yuzu were collected in a strainer net, and dried them for about a week.

In case of yuzu, you can cut off the endocarp (white part) with scissors or a cutter to make it easier to dry.

Step 2: Soaking in alcohol

Bottles were filled with disinfectant ethanol and mikan peel or yuzu peel (1), and left for a few days (2).

☆Recipe
In this time, peels of 3 to 4 medium-sized mikans (44g) and peels of 1 large-sized yuzu (oni yuzu) (64g) per about 100ml of ethanol were placed in bottles for 5 days.

Finished!!!

From mikan and yuzu peels, we could extract brown essential oils as shown below.

Mikan	Yuzu

This is the color change of ethanol applied to the peels of mikan and yuzu for five days.

(Illustrations of mikan and yuzu on graphs are referenced from “Irasutoya” and “public domain Q” copyright-free image collections, respectively.)

About graph:
We thinking that intensities of color might be indicator of how much essential oil has been extracted, 1.5 mL portion of alcohol collected on 0, 1, 3, and 5 day for extraction.After collection of all samples, samples were put on a white plastic palette (purchased at a hundred-yen store) and take photo by smartphone (a part of photos are shown in the graph panel). The captured images were converted to grayscale (256 steps), and measured their color depth (0 is white, 255 is black) using the image analysis software (imageJ, free software).
Since the graphes show that the color intensity did not seem to increase much after the third day for mikan and after the first day for yuzu, we thought that 5 days would be sufficient for extraction.

Impressions

We were surprised that we could extract essential oils with refreshing citrus smell more than we expected.The mikan and yuzu essential oils had their own different smells.

You can make the same essential oils from various citrus fruits (kabosu, lemon, etc.), so it would be interesting to make essential oils using different citrus fruits in the different seasons. Just putting alcohol and citrus peel in bottles for a few days can not only make it fragrant, but it can also be usable for various purposes such as cleaning!

We hope you will try it.

References

Shohei Sato's blog
https://satoshohei.com/2018/01/mikan-oil/ (In Japanese)

2021.01.11	Deadline for submission of web contest.
2020.12.30	We experimented with essential oil extraction (extraction with alcohol).（～2021.01.04） (Let's make it)
2020.12.24	We experimented with essential oil extraction (compression method).
2020.12.23	We had the opportunity to interview the cafeteria staff at our school. (Interview)
2020.12.22	We have been chosen as semi-finalists.
2020.11.24	Deadline for submission of web contest.
2020.11.18	Internet questionnaire for all student of our school (Shibaura Institute of Technology Kashiwa Junior High School) (Questionnaire)
2020.11.16	We conducted a phone interview with a nutritionist at an elementary school in Ibaraki. (Interview)
2020.11.14	We used eggplant skin and coffee grounds to dye. (Let's dye!-vol.2-)
2020.11.09	We used onion skin to dye. (Let's dye!-vol.1-)
2020.10.22	We have been chosen as a school representative.
2020.07.25	We entered the web contest.
2020.07.11	We formed a team.