TABLE OLIVES

Olives are a drupe, or stone fruit, that contain a bitter element, oleuropein, a low sugar content (2.6 - 6%), unlike other drupes that contain 12% or more, and a high oil content (12 - 30%) depending on the period and variety. These characteristics make the olive a fruit that cannot be eaten plain. It first has to be treated, with the method varying considerably from one region to another and according to the variety. 

Certain olives are exceptions. As they ripen, they turn into sweet fruit on the tree itself, after fermenting in most cases. One known case is the Thrubolea variety in Greece. The olive's oleuropein needs to be eliminated because of its very strong bitter flavor, although it isn't harmful. The olives are usually treated with sodium hydroxide or potassium hydroxide, brine or successive washings, depending on the systems or local traditions.

Using olives on the table depends on their size which is an important presentation factor. Medium olives weigh between 3 and 5 g, while large ones weigh more than 5 g. The pit should separate easily and a 5 to 1 ratio between pulp and pit is acceptable, though the commercial value rises as this ratio goes up. The olive's skin should be thin, elastic and resistant to blows and the action of alkaline or brine. The high sugar content of the pulp is favorable; a lower limit of 4% is allowed particularly for fermented olives. It is desirable that the oil content be as low as possible because too much oil detracts from the product's conservation properties and the texture of the fruit.  Only with certain kinds of black olives is a moderate or high oil content acceptable.

Green olives
Obtained from fruit harvested during the ripening cycle, before veraison and when they reach a normal size, the olives are generally picked by hand at the point when the leaves show a slight change of color, from green to slightly yellow, and the pulp begins to change texture but before it softens. The olive's veraison should not have begun. Attempts have been made to harvest table olives mechanically in some cases, but because of the high rate of bruised fruit, it is necessary to immerse the fruit in a diluted alklaine solution immediately at the foot of the tree. Olives that have been freshly picked, if possible the same day, are transported to the processing facility for treatment. The main olive treatment systems are fermented (Spanish style) and unfermented (Picholine and American style). 

Spanish or Sevillian style
The olives are treated with a diluted bleach solution (sodium hydroxide) to eliminate and transform the oleuropein and sugars and to form organic acids that promote later fermentation and to increase the fruit's permeability. The bleach concentration varies from 2 - 4%, depending on the degree of ripeness, temperature, variety and water quality. The processing takes place in containers of varying capacity so that the solution perfectly covers the fruit, which remains at this stage until the bleach has permeated 2/3 of the pulp. Then the bleach is replaced by water that draws out the remaining residue. This operation is repeated several times. Prolonged washings eliminate the particles of bleach but also the soluble sugars necessary for later fermentation. 

Fermentation takes place in appropriate receptacles, with the olives covered in brine. Traditionally wooden casks were used. Today large containers with non-reactive internal surfaces are used. The brine draws out the juice from the fruit's cells and forms a culture liquid adequate for fermentation. They begin with concentrations of 9 - 10%, which are quickly reduced to 5% because of the high water content of the olives. Then they olives move on to washing, various treatments and a final brining before being packed. 

Ripe olives
They are obtained from fruit picked at almost total maturity, once the color proper to each variety and the corresponding oil content has been reached. The treatments applied to different categories of olives are very numerous. We'll only mention the most common commercial ones. 

Black olives in brine
This is a preparation method typical of Greece with the Conservolea variety that provides about 200 olives per kg, and of Turkey with the Gemlik variety. The olives are picked when ripe, but before being overripe and before the formation of wrinkles caused by frosts. These olives have to be transported to the factory as quickly as possible, where they are sorted, washed and immersed in an 8 - 10% brine solution. The industry uses large vats, 8-10 t., while artisans still use wooden barrels. At the beginning of the fermentation, they prevent the olives from coming into contact with the air and close up the vats tightly. The brine stimulates the microbial action for fermentation and reduces the bitterness of the oleuropein. The brine's concentration goes down to 6%, requiring it to be increased again to 8 or even 10%. Homogenization occurs thanks to the action of a circulating pump. When the bitterness is sufficiently reduced, which is variable, the fruits can be sold. The color has lost its intensity during the process, which is corrected by exposing the olives to air for 2 or 3 days. They are sometimes treated with 0.1% iron gluconate to blacken them more intensely. Finally the olives are sorted and conditioned in coated barrels or cans and filled with fresh 8% brine. They are popular on the market because of their flavor and slight bitterness. They are also conditioned with vinegar (25% of the volume of the brine) and heat processing. They add a few grams of oil to each can to form a floating layer. This processing is typical of Greek Kalamata olives, long and medium sized, that are slit laterally before being placed into tins.

Dry-salted black olives
Also of Greek origin, these olives are prepared with the Megaritiki variety, with overripe fruit. Briskly washed, they are then placed into baskets, alternated with layers of dry salt equal to 15% of the olives' weight. The product is not very bitter, is salty, looks like a raisin and is intended for the local market.

Seasoned olives
To conclude we should also mention some of the various table olive preparations from different olive-producing regions, such as those treated solely in water to remove the bitterness, fruit that is crushed or slashed in advance, which facilitates the washing process. They are often eaten after having been flavored with herbs, pieces of orange, lemon ,garlic, paprika, marjoram, etc. 

Stuffed olives
These are green pitted olives stuffed with a piece of pimento (sweet red pepper). 

With the special collaboration of the International Olive Production Council