The fruit has been considered a choice food at all times. It has
appeared at the feasts of epicures, both ancient and modern, as a
relish, and to be eaten at the end of the repast as part of the dessert,
and at all times it has also furnished a staple food for the poor in the
Orient and in Greek and Latin countries. Those who were well provided
were admonished to have care for those less fortunate: “When thou
beatest thine olive tree, thou shalt not go over the boughs again; it
shall be for the stranger, for the fatherless, and for the widow.”
(Deuteronomy XXIV., 20.) The people obliged to live frugally have found
it a great resource, particularly in Lent and for those at a distance
from the sea unable to obtain fresh fish. It is said that Plato
preferred olives to all other foods, and often made a meal on them
alone.
Though olives are known and consumed throughout the civilized world,
comparatively few persons, aside from those living in the regions of
their cultivation, know that olives have to undergo certain treatment
before they can be eaten. It is a common practise in olive regions to
encourage the visitor to taste the fruit directly from the tree. The
fruit, both green and black, looks so fine and tempting, that the
disgust on tasting is correspondingly great. It is claimed that some of
the older varieties could be eaten without preparation, that they dried
naturally, and were sweet like raisins.
The olive contains a bitter and acrid substance or substances which must
be removed before the olives are edible. It is referred to in most of
the literature as a “bitter principle”, and has been called an acid, a
tannin, and more recently a glucoside. Cruess has repeated the work of
the various investigators, who claimed these different substances, and
as a result has come to the conclusion that it is a glucoside, that is,
a combination of glucose with another compound.
In immature fleshy fruits there is usually an accumulation of acids,
tannins, and sometimes starch. As ripening proceeds, carbohydrates and
aromatic substances are formed, and the bitter, acrid, or astringent
taste disappears. In the olive there is no starch found at any stage of
maturity. Glucose has been found in all stages, and is supposed to be
the substance from which the oil is formed. The oil is in very minute
quantities in the fruit up to the time when the pit is formed, from then
on it increases gradually up to its maximum when the fruit is not quite
mature. In the plant economy the fat or oil is one of the most important
food reserves of plants. All parts of the fruit--rind, flesh, stone, and
seed--contain oil, the fleshy part, forming about 80% of the fruit,
containing the largest amount.
Contrary to the condition existing in most fruits, the bitterness
remains through all stages of development in the olive. A substance of
glucosidic nature, given the name “oleuropeine”, has been isolated, and
found to be of extreme bitterness. This may be the substance or one of
the substances which cause the inedibility of the untreated olive.
The oil is the most important constituent of the fruit on account of its
high food value and its use in the industries. It is used to a large
extent in cold countries and also in dry countries where there are few
cattle, the oil taking in the various culinary operations, the place of
butter and other fats.
Among the ancient Jews the oil was considered indispensable and as
necessary as bread. An abundance of oil was looked upon as a blessing
from God. Vast public storehouses were constructed to hold it for the
scarce years. To the Greeks the three indispensable foods were oil,
grains, and wine, the oil entering into most of their dishes. The Romans
had a large trade in the oil, and it was also used, to a large extent,
in their domestic cooking. In Italy and Spain street vendors fry
fritters in the oil and sell them while hot. It has considerable use in
conserving fish, particularly sardines. The higher grades of French,
Spanish, Norwegian, and American sardines are packed in olive oil. This
use has been extended in recent years to the packing of tuna fish.
Olive oil occupies a high position as a vegetable fat. Many others have
been prepared and offered as substitutes, and if judged by chemical
composition alone, give practically equal food value, but are lacking in
the delicious flavor which makes olive oil distinctive and gives it a
superiority over all other oils.
The oil is a large factor in the industries; it serves as an extractive
of perfumes, as a constituent of fine, smooth soaps, and as a lubricant
in watch factories. Formerly the lower grades were used commonly for
lubricating purposes, but with improved methods of clarifying and the
greater expense attendant on its use, it has been superseded by cheaper
lubricants.
An enormous quantity has been and is still used in religious ceremonies,
in the ordinations of the clergy and rulers, and anointing in the
sacraments, besides by old world peoples generally in the lamps in the
churches and temples, many of which are kept burning continually. An
idea of the vast amount consumed for this purpose can be obtained from
the fact that in one mosque alone there are 1,200 lamps burning
constantly, and requiring about 25,000 kilos of oil annually.
In medicine it has been and is still used extensively. The ancients
rubbed it on their bodies to make the muscles supple and to cleanse and
protect the skin, particularly after bathing, and it still functions for
these purposes. It was used to heal wounds, in liniments, and as a mild
laxative. At present it is a constituent of liniments, ointments,
cerates, and plasters. The people who are habitual patrons of the olive
and its oil are noted for their smooth, beautiful complexions. It is
said “the warm rosy complexion of the Italian and Sicilian women is due
to the free use of olive oil as much as to the air and climate of their
country.”
The residue or marc which remains after the oil is extracted is used as
a food for sheep and hogs, for fertilizer, and for fuel, and there is
obtained from it a clear, illuminating gas.