Olive - Production and Processing

Producing table olives: green olives, iridescent olives and black olives

Fresh and raw, the olives are not edible, or rather, they have a particularly unpleasant taste; this is due to the massive presence of oleuropein (bitter taste) and tannins (bitter taste that "binds" in the mouth); these substances are appropriately hydrolyzed or inactivated by specific procedures (soaking, fermentation, etc.).

Table olives can be prepared differently depending on the product to be obtained: green olives, iridescent olives and black olives. For a similar distinction, the first variable to be analyzed is the degree of veraison (maturation) of the olives themselves.

1. Harvesting: it is a much more complex and delicate operation than that for olives destined for oil production, as drupes MUST remain absolutely INTEGRATED for table olives; this avoids the possibility of an enzymatic browning of the pulp; the collection, therefore, must be carried out "by hand".

   To produce green table olives it is necessary to find olives that have reached the size of a normal drupe but have not yet begun the maturation process. On the contrary, to obtain iridescent table olives it is essential to select drupes with a green to purplish color or a vinous red color, which have kept a still green pulp under the peel (indicator of a not yet complete maturation). Obviously, to produce black table olives it is necessary to choose those that have reached full ripeness.

2. The next procedure is the cleaning of the olives, ie the removal of leaves, branches and other small residues.
3. This is followed by the debasement or annihilation of the bitter taste typical of fresh olives: it can be done through an alkaline treatment, by immersion in a liquid that dilutes the molecules responsible for the unpleasant taste (oleuropein) or through some biological procedures such as lactic fermentation .
4. Conservation : it can take place in brine, with dry salting, in a modified atmosphere, for cooking and packaging, by preserving or acidifying agents. NB . Oleuropein, if hydrolyzed, breaks down into aglycon and sugar.

Processing methods of green, iridescent and black table olives

The table GREEN olives are preserved with different systems, respectively: Sivigliano, Castelvetrano and natural; the CANGIANTI table olives prefer the "natural system" and the natural Greek one. Finally, black table olives require systems from the California, Kalamata and "baked olives". In summary:

• Sivigliano system: sorting, calibration, treatment with soda, washing, brine, fermentation, calibration, packaging, pasteurization.
• Castelvetrano or soda system: sorting, grading, sodium-alkaline solution, softening, fermentation.
• Natural system: sorting, grading, crushing and pitting, brine, fermentation, sizing, packaging, pasteurization.
• Natural system, Greek version: sorting, calibration, brine, fermentation, calibration, engraving, washing, brine, immersion in vinegar, packaging with olive oil.
• Kalamata system: sorting, grading, etching, washing, pickling, immersion in vinegar, packaging in olive oil.
• Californian system: sorting, grading, brine, soda treatment, air oxidation, washing, treatment with ferrous salts, brine, pasteurization, calibration, packaging and sterilization.
• Dry salt system: sorting, dehydration with dry salt.
• Baked olives system: sorting, grading, blanching, adding dry salt, oven drying, packaging.

Bibliography:

• At the table and in the kitchen with olives - L. Caricato - New techniques
• New dictionary of applied commodity and chemistry - Hoepli

Reference websites:

• //en.wikipedia.org/wiki/Olive