The production of table olives

The consumption of the olives as a food resource has a long history: they were eaten by our ancestors a long before the discovery of olive oil. Their nutritional value and their easiness to be found and preserved have always been solid argument to their use.
A lot of archaelogical proof has been given related to the use of table olives.
Ancient writers have often made reference to the olives in their "cookbooks" and manuals. Lucio Giunio Moderato Columella, for example, has passed on to us tasty recipes to prepare olives with grape must, vinegar, fennel seeds and lentiscus.

CHARACTHERISTICS OF THE OLIVES
Olive varieties may be divided into different categories according to their suitability to produce oil, table olives or both. The ones that can be used in both manners are said to be " dual-purpose" olive cultivars and are characterized for a bigger size, a higher pulp/core ratio and a relatively low oil content.
Characteristics of the fruit
Olive is a drupe or "stone fruit" with a central single seed (pit), surrounded by edible pulp and an external peel. Size and shape of the olives greatly vary depending on the cultivar type. On an average, a fruit weighs about 3-15 g. Raw fruits are green and turn yellow to purple-dark as they ripen further. Olives are generally picked at different stages depending upon the variety they belong to and whether they are destined to be used as table fruits or pressed into oil.
Olive has a bitter component (oleuropein), a low sugar content (2.6-6%) compared with other drupes (12% or more) and a high oil content (12-30%) depending on the time of year and variety.
These characteristics make it a fruit that cannot be consumed directly from the tree and it has to undergo a series of processes that differ considerably from region to region, and which also depend on variety.
Oleuropein, a phenolic glucoside which is distinctive to the olive, has indeed to be removed as it has a strong bitter taste. Depending on local methods and customs, the fruit is generally treated in sodium or potassium hydroxide, brine or successively rinsed in water.

PRODUCTION OF TABLE OLIVES IN THE LATIUM
The production of table olives is an important part of Italian olive-growing culture and has a significant and increasing economic role.
The most common varieties to be processed as table olives in the Latium are two: the Itrana variety, widespread in the province of Latina, and the Leccino variety, most common in the Sabine, among Roma and Rieti. They both are dual-purpose olive varieties.
The olive fruit can be picked at any stage from the beginning of ripening, when it is green, until it is black and fully mature. To render the fruit edible - as mentioned above - it is important to remove some or all of the bitter oleuropein, which is found in all olives in varying amounts. The fruit is then preserved by one of a number of possible processes.
Methods of oleuropein removal and preservation are dependent on many factors, including the olive cultivar, fruit maturity, growth conditions, and cultural preference. The three most widely used classifications of table olives are indeed based on fruit color (green olives, olives turning colour, black olives), processing method, or processing style.

There are different methods for the production of table olives. In the Latium, table olives are generally simply washed with water or weak brine solution and then undergo lactic fermentation in brine solution, which preserves them and increases their palatability. Factors such as temperature, pH of the brine solution, concentration of the brine solution, available microorganisms, reducing sugar content of the olives, and exposure to light and temperature all affect the quality of the processing. This "natural" method allows olives to preserve the largest part of their antioxidants and their enormous nutritional value.