Page 415 - Biosystems Engineering

392 Cha pte r F o u r tee n

Several component of Olea europaea plant contain bioactive poly-
phenols. Typical phenols of O. europaea are oleuropein and hydroxy-
tyrosol; both these phenols show antioxidant properties not only
during olive oil oxidation but also in cellular and animal models.
Recently, the feasibility of isolating, extracting, and producing
olive oil phenols as pure compounds (to use them as antioxidant and
for other biological properties) has been investigated extensively.
An olive oil industry, produces also high amounts of organic by-
products besides the oil. A considerable quantity of native olive poly-
phenols is lost in the above-said by-products and so these have been
considered a source of bioactive olive polyphenols.

14.2 Olives and Relative Olive Mill Products
The olive tree (O. europaeae) is a plant cultivated typically in Mediter-
ranean countries and the olive fruits have been used to produce edi-
ble oil since ancient times.
Olives are drupes, consisting of four parts: epicarp (skin or peel),
mesocarp (pulp or flesh), endocarp, and kernel. A representative
chemical composition of olive fruit is showed in Table 14. 1 (Niaounakis
and Halvadakis 2004).
Most of the oil is in the pulp with content variable in function to
climate, season, variety, and ripeness of the fruit.
Mediterranean countries produce 95 percent of the total world
production of olive oil, estimated to be 2.5 million tons per year and
European Union countries produce 75 to 80 percent of the world’s
olive oil. The largest European producers are Spain, Italy, and Greece,
plus Portugal and, to a lesser extent, France, Cyprus, and Croatia
(IMPEL 2003).

Components Olive Pulp Stone Seed
Water 50–60 9.1 30.0
Oil 15–30 0.7 27.3
N total 2–3 3.4 10.2
Sugar 3.0–7.5 41 26.6
Cellulose 3–6 38 1.9
Minerals 1–2 4.1 1.5
Polyphenols 2.3–3.0 0.1 0.1–1
Other compounds — 3.4 2.4

TABLE 14.1 A Representative Chemical Composition of the Olive Fruit (%)