According to I.O.C (International Olive Committee) table olive is the product “prepared from the healthy fruits of olive-cultivated varieties Olea Europaea Sativa, which are chosen for their volume, shape, meat / bone ratio, flavor, firmness and ease of Detachment of the bone making them particularly suitable for transformation.
The fruit initially is green, but changes to a violet or black color as it matures, decreasing the moisture content and increasing the oil content, depending on the variety. Olive has a low content of sugars (from 2.6 to 6%, in contrast to the rest of the drupes reaching 12% or more) and a high oil content: from 12% to 30%, according to State of maturity and variety of olives.
The green olive is a drupe that can not be eaten directly from the tree, not only because of its hardness but also because it contains a bitter (oleuropein) principle, which although it is not toxic, is extremely bitter, although some variety becomes sweet fruits in The tree itself as the maturing process progresses.
All these characteristics make the olive have to undergo processes that vary depending on the variety and the geographical area where they occur; Treatments with sodium or potassium hydroxide, brine or successive washes with water, according to local systems and habits.
Freshly harvested olives from the field after shaking or vibration arrive at the processing plant, where they are allowed to air and release some of their moisture.
In the processing plant, after the selection, wash in soft water and soak in an alkaline solution (brine at a concentration of approximately 9%) at a constant temperature to eliminate its natural bitterness. The duration of the process depends on the olive variety and the temperature. This is the usual method for the treatment of green olives, and the most popular in Spain as internationally-that is the one used for Spanish-style olives or Seville- which consists of completely submerging them. The solution should only penetrate Through two thirds or three quarters of the olive flesh, but never to the bone, in order to maintain the taste of the olives. In this way the fermentation takes place, transforming the sugars of the fruit into lactic acid, giving rise not only to a product that will keep in perfect state of conservation, but also presents excellent gastronomic qualities.
Like other fermented products like wine and cheese, olives need to be cured. Not all types of olives react with processing in the same way. Certain varieties of olives have always been used for the extraction of oil, while others, of which there are less, for processing such as table olives.
Table varieties generally have to be of reasonable size, preferably spherical, with a high pulp-bone ratio. They should have a thin, elastic skin. Finally, the high sugar content is beneficial as it facilitates fermentation, while low oil content improves conservation properties and gives firm fruits.
The varieties traditionally considered the best are the Manzanilla and Gordal of the Seville area, along with the Hojiblanca. These are the most important commercially. All of them are cultivated mainly in Andalusia, in the south of Spain. Other varieties important for processing as table olives are the Manzanilla Cacereña and Carrasqueña, which usually come from Extremadura in southwestern Spain. At a distance from these are the Verdial, Arbequina, Empeltre, Moruna, etc. Many of them are processed for local consumption. The entire process requires a minimum of two to three months.