Olives and Olive Oil - Tropical and Subtropical Fruits: Postharvest Physiology, Processing and Packaging - page 500

various disorders, such as cardiovascular complications,
cancer (colon, breast, prostate), and hypercholesterolemia
(Heredia et al., 2003). Chlorophyll and carotenoid com-
pounds are also present in green and turning-color table
olives. These pigments have considerable potential in pre-
venting damage to human health from mutations, includ-
ing cancer and other degenerative disorders (Bendich and
Olson, 1989; Dashwood, 1997; Mınguez-Mosquera et al.,
2008; Ferruzzi and Blakeslee, 2007).
Therefore table olives constitute a good source of healthy
compounds in the diet. Furthermore, table olives could
be used as a vehicle for incorporating probiotic bacteria
and transportating bacteria cells into human gastrointesti-
nal tract (Lavermicocca et al., 2010).

Preparation operations
*Olive harvesting
*Shipping
*Cleaning and washing

Milling

Mixing

OLIVE OIL
As stated before, olive oil is the main product derived from
olive fruits (90% of olive production). Olive oil is the oil
obtained solely from the fruit of the olive tree ( Olea eu-
ropaea L.), to the exclusion of oils obtained using solvents
or reesterification processes and of any mixture with oils of
other kinds (IOC, 2010c). Olive oil is used throughout the
world probably due to its recognized nutritional properties.

Solid-liqu id separation

Selective filtration Pressure extraction Centrifugation

Three Phases Two Phases

* Solid olive-pomace * Solid olive-pomace

* Residual water * Olive oil

* Olive oil

Olive oil processing
A typical olive oil processing outline is shown in Figure
26.5. A detailed description of various steps involved in
olive oil processing is given in the following paragraphs.

Liquid-liquid separation

Preparation operations
Olive harvesting
This is one of the most important stages in the process of
obtaining virgin olive oil since it largely determines the
cost of virgin olive oil and directly contributes to its qual-
ity. As much as possible, the optimal degree of ripeness in
the olives should be determined, as this affects not only the
fruit's maximum oil content but also other compounds that
are responsible for its sensory properties. The ideal method
involves picking the fruit directly from the tree in order to
avoid damaging the fruit and the tree (as for table olives;
see section “Harvest, Storage, and Shipping Practices”).
However, this is not always possible due to cultivation tech-
niques, the tree canopy, terrain features, and price, which
may require mechanical systems to facilitate the task, such
as vibrating machinery. To date, Spain has developed new
varieties of olives where the size of the tree has been se-
lected for an intensive crop (2000 trees per hectare) to use
harvesting machines designed for “hedgerow” cultivation
(Rallo et al., 2008).

Storage

Figure 26.5. Flow diagram of olive oil processing.

In any case, the objective should be to avoid harvesting
fruit that has fallen to the ground at all costs as the fall usu-
ally damages the fruit, which negatively affects the quality
of the olive oil.

Shipping and postharvest losses
Care should be taken so that fruit is not compressed during
transportation. The optimal system for accomplishing this
is the use of plastic boxes with holes for providing the fruit
with ventilation and to help disperse the heat produced (Di
Giovacchino, 2003). Ideally, the fruit should be processed
on reaching the mill, to avoid undesirable reactions. This
is not always possible, however. In this situation, the fruit
undergoes a series of transformations that lead to a loss
of quality that includes fermentation (due to increased