Oleuropein is the main polyphenolic compound of the olive olea europea, from which it derived its name. It was found to exist in olive oil in 1908 by Bourquelot and Vintilesco, who also provided the name. Much later, in 1960, Panizzi, Scarpati and Oriente proved that the atomic structure contained glucose and an acid known as elenolic acid. This acid was obtained through hydrolysis of an olive extract and phosphoric acid. In 1962 it was introduced as a medicine to treat high blood pressure.
Oleuropein is found in both the leaves and fruit of the olive tree. The bitter taste of olives is due to the presence of oleuropein which is found to exist more in the unripe fruit.
Over the last few years oleuropein and other polyphenolic derivatives have been studied for their antioxidant, bactericidal and bacteriostatic properties, as well as their effectiveness in reducing blood platelet aggregation. Oleuropein and its derivatives play an important role in plants, given their defensive function: Due to the presence of antioxidants, plus the bitter taste, it protects olive trees from destructive organisms and insect attack.
Significant quantities of oleuropein are to be found only in the throumba olive, amounting to 550mg/g of olive pulp, or 1,2mg/an olive (for black olives it is 18,2g/g of olive pulp and for thick black olives 8,9 g/g of the pulp accordingly). Extracts from recent studies by the Pharmaceutical Department of the University of Athens and Patras have been published in the American journal of Agricultural and Food Industry.
These considerable differentials in oleuropein content can be put down to the olive type and to the specific processing methods applied to them. Given the above, it can be concluded that olives and olive oil rich in precious antioxidants are of great benefit to daily nutrition. The varying amounts of oleuropein in the different sorts of olives should clearly be also taken into consideration.
So why not make the Thrumba olives your own special choice? It is extremely rich in oleuropein and, thanks to a special enzyme phoma oleae, it loses its bitterness while it ripens and blackens. In this way, the olive "wrinkles" and loses its bitterness before being harvested, thus eliminating the need for further processing. Additionally, the olive can be kept in 40% sea salt for 40-60 days, after which it becomes soft and acquires its delicious taste and is ready for consumption.