During
extraction of olive oil, highly polar polyphenols are retained
in the olive pulp, or alpeorujo, which is used as the raw
material for olive powder.
The
principle polyphenols in olives are tyrosol and hydroxytyrosol,
which are both derivatives of the antioxidant oleuropein.
These phenolic olive compounds have some of the highest
antioxidant activity of any similar compound found in nature.
Polyphenols, tocopherols and other natural antioxidants
found in olives are known to prevent lipid oxidation and
formation of free radicals in the body, which contribute
to tissue damage.
The
ability of antioxidants in food to neutralise free radicals
can be measured and expressed by the oxygen radical absorbance
capacity (ORAC). Studies have demonstrated that there is
a strong correlation between antioxidants in food and ORAC
values. Flavonoids are one of the many naturally occurring
components which contribute to the antioxidant activity
of foods.