Processing for Quality
Many processing factors affect the quality of olive oil including harvesting and transport conditions, crushing speed, sieve grid size, malaxation time and temperature and storage conditions.
The olive tree is one of the oldest plants to be cultivated and is believed to have originated in Iran and Syria around 6,000 years ago. From there, it spread around the whole Mediterranean and, today, the olive tree can be found all over the world.
Great developments and changes have taken place in the production of olive oil during the centuries.
The first techniques developed for the extraction of olive oil were based on crushing the fruits, breaking the structure, using compression systems like the ‘molae’ and extracting the oil with a wedge or screw press.
The modern extraction process to produce extra virgin olive oil (EVOO), the highest olive oil category, generally involves the following steps:-
▪ Harvest and transport of olives to the mill
▪ Belt elevator with deleafer
▪ Washing
▪ Crushing
▪ Malaxation
▪ Decanter process
▪ Centrifugal olive oil separator (‘polishing’) ▪ Filtration
▪ Bulk storage
▪ Bottling
General Aspects
In order to determine processing steps, the olive fruits’ condition, maturity and moisture content must be determined to decide on the most appropriate strategy for paste preparation and oil separation. The fruit condition and water content will also determine if the operator should use processing aids such as talcum powder or enzymes to improve oil extractability and decanter working capacity.
Harvest and Transport
It is absolutely necessary to treat olives very carefully during harvest as any damage to the fruits leads to fermentation, which begins after fruits are harvested from the trees. During internal fermentation, enzymes are activated to destroy the fruit to set the pit free.
Therefore, storing olives in the grove over several hours or days should be avoided. The best storage conditions are cold and in shade. Olives should ideally be processed immediately after delivery to the mill or their storage time kept to a minimum. Therefore, storing olives in the grove over several hours or days should be avoided. The best storage conditions are cold and in shade. Olives should ideally be processed immediately after delivery to the mill or their storage time kept to a minimum. Go to Page 22 at this link for More