Olives and Olive Oil - Tropical and Subtropical Fruits: Postharvest Physiology, Processing and Packaging - page 498

called “green staining,” during preservation in brine. This
alteration is seen as bluish green spots distributed over
the skin and is due to the formation, and localized accu-
mulation, of several copper-chlorophyll derivatives in dif-
ferent degrees of oxidation (Gandul-Rojas et al., 1999b;
Gallardo-Guerrero et al., 1999), being from endogenous
origin the copper involved (Mınguez-Mosquera et al., 1995;
Gallardo-Guerrero et al., 2002). The appearance of copper-
chlorophyll complexes in table olives implies that, during
industrial processing, there has been a strong oxidative dis-
integration of the chloroplast in at least some fruits, allow-
ing contact between the chlorophyll pigment and the copper
fruit (Gallardo-Guerrero et al., 2003, 2007).

during processing. Therefore the main acids found in the
packed product (lactic and acetic acids) are those produced
during fermentation or storage or added to the cover liquid
(L opez-L opez et al., 2007).
Regarding table olives' micronutrient composition, the
different stages of the process lead to an increased percent-
age of ash in the solution because the pulp absorbs salts.
Although the mineral content (1.5-7%) differs among the
various trade preparations, all of them increase content in
sodium, the most abundant element, because it is used in
brine. In the case of black olives, iron content also increases
due to the use of ferrous salts to stabilize the color of the
product. With regard to other minerals, it stands out that
most of them are found in higher proportions than in other
vegetable products. Concerning vitamins, table olives con-
tain vitamins E (tocopherols), B 1 (thiamine), B 6 (pyridox-
ine), and C (ascorbic acid), and provitamin A because of its
β

Nutritional profile and health benefits
Nutrient composition and the effect of processing
on nutrients
Table olives are important components of the Mediter-
ranean diet and are greatly consumed all over the world.
They have a high nutritional value due to their balanced
fat content, since they have more unsaturated fatty acids
than saturated ones, and high monounsaturated oleic acid
content in particular. Consumption of table olives also
contributes essential fatty acids, fiber, vitamins, minerals,
and polyphenols. The table olive's nutrient composition is
basically the same as the fresh fruit's (Table 26.1) with
the changes resulting from the olive preparation process.
The main components of table olives are therefore wa-
ter (60-85%) and fats (9-30%). The latter are the source
of olive oil, which is well known and highly valued for
its recognized nutritional properties. Table 26.6 shows the
composition of table olives prepared according to differ-
ent trade preparations. Those values are approximate, since
they depend on the olive variety, type of olive, and style
being processed (whole, pitted, stuffed, salad, etc.).
In general, the fatty content of the fruits will be higher for
preparations using more mature fruits. As a result of treat-
ing the fruit with NaOH and subsequently washing it with
water, which is the process used for most table olive prepa-
rations, a portion of the water-soluble compounds present
in the fresh fruit is lost. During fermentation, sugars pass
into the brine and are metabolized by micro-organisms. As
a result, table olives have almost no sugar content. With re-
gard to other macronutrients, table olives have low protein
content (1-4%). However, they do contain all of the essen-
tial amino acids in relatively high quantities, making them
a high-quality food source (L opez et al., 2007). The table
olive's fiber content (2-6%) is also quite significant. The
organic acids present in raw olives are practically removed

-carotene content. These are found in variable amounts de-
pending on the olive type and preparation style (Hassapidou
et al., 1994; L opez et al., 2005; Monta no et al., 2005; L opez-
L opez et al., 2008).
Table olives also contain a number of bioactive com-
pounds that give them considerable functional value.
In green olive preparations, chlorophyll and carotenoid
pigments are found in significant quantities (Mınguez-
Mosquera et al., 1989, 1994; Mınguez-Mosquera and
Gandul-Rojas, 1994; Mınguez-Mosquera and Gallardo-
Guerrero, 1995). In the same way, all table olive prepa-
rations show a high polyphenol content. Hydroxytyrosol
is the most abundant phenolic compound since it oc-
curs as a result of the hydrolysis undergone by the two
main phenols in the fresh olive, oleuropein (Amiot et al.,
1990) and hydroxytyrosol- β -4-D-glucoside (Romero et al.,
2002), during table olive processing. The great impor-
tance that phenolic compounds of table olives may have
from a nutritional point of view is obvious from the large
number of researchers currently interested in studying
them (Romero et al., 2004; Pereira et al., 2006; Othman
et al., 2009; Zoidou et al., 2010). To enhance the value
of this fruit from a nutritional point of view, the triter-
penic acid contents (maslinic and oleanolic acids) of ta-
ble olives have been studied for the first time (Romero
et al., 2010).

Health-beneficial compounds
Table olives are rich in substances to which numerous bi-
ological properties have been attributed in recent years,
especially polyphenolic compounds and triterpenic acids.
Many of these studies were related to olive oil consumption.
However, we must point out that table olives in most trade