Waste water from olive oil production in the Mediterranean region has long been an environmental issue. Research has now evolved an ecological problem into a commercial success; with the help of scientists, this waste water has become a source of antioxidants for use in food through a process developed to recover active constituents. Olives and the oil derived from olives, particularly extra virgin olive oil, are rich in simple and complex phenolic compounds with potent antioxidant properties believed to have a protective action on human health. However, during olive oil processing, a large fraction of these phenols are lost in mill wastewater and released into the Mediterranean environment.
One of the phenolic compounds transferred from the olives into the waste water is hydroxytyrosol. Several studies were conducted with the waste water to test the potential bioactivity or usefulness of hydroxytyrosol. Capsules of the waste water extract, containing 50 mg of hydroxytyrosol, were prepared and given to human volunteers for several days. Ingestion of the water capsule resulted in marked decrease of serum thromboxane B2 (an index of pro-blood clotting activity) production. These observations indicate that hydroxytyrosol inhibits the activity of the platelet cycloxygenase system, an activity similar to that of aspirin.
Researchers maintain that additional work is needed to elucidate the biological activity of the extracts on various biological processes e.g. inflammation or endothelial function and its efficacy in functional foods.