I never thought of a blueberry as an oil source until recently, when I visited with cosmetic chemists. Blueberries contain a very small or immature seed that can be pressed for oil. Some varieties have a more defined seed, but for the most part you will not even notice it. The seed is pressed into a very pleasant oil and marketed in the cosmetic industry worldwide.
Here is what one of the suppliers in the USA say on the spec sheet: Fruitsmart in Washington State says:
Blueberry seed oil is prepared by the mechanical cold press expeller processing of blueberry seeds. No solvents or chemicals are used during any step of production. The process yields unrefined blueberry seed oil which is then lightly filtered and purged with nitrogen and packed securely in appropriate containers. This product is processed, packaged and shipped in accordance with Current Good Manufacturing Practices and in compliance with the United States Food, Drug and Cosmetic Act of 1938 as amended.
Appearance: light green
Aroma: no off notes (I say it has a wonderful blueberry aroma!)
Solubility: lipid soluble
Extraneous matter: clear
Peroxide value: <15mg/kg
Specific gravity: 0.923
Now, the big question. What is it used for. I talked to cosmetic chemists who are currently using it in a whole variety of skin applications. Just for the aroma of real blueberries it is worth the pricy price tag! (Send me a note and I will fill you in). According to oil chemists, the blueberry oil has some very interesting functional characteristics for food and non food uses including special applications in mechanical engineering.
Now this is all interesting stuff, and I must get to work to update a new column on the Blueberry supplier list! I understand there are a few suppliers.