Cooling treatment of olive paste during the oil processing: Impact on the yield and extra virgin olive oil quality

- A technological innovation is introduced in mechanical extraction process of olive oil.
- For the first time the olive paste is undergone to a cooling treatment (CT) after the crushing phase.
- The rapid cooling conditioning of olive paste has a positive impact on extra virgin olive oil quality.
- The CT improves the phenolic concentration and modifies the volatile fraction of olive oil.

In recent years, the temperature of processed olives in many olive-growing areas was often close to 30 °C, due to the global warming and an early harvesting period. Consequently, the new trends in the extraction process have to include the opportunity to cool the olives or olive paste before processing to obtain high quality EVOO. A tubular thermal exchanger was used for a rapid cooling treatment (CT) of olive paste after crushing. The results did not show a significant difference in the oil yield or any modifications in the legal parameters. The cooling process determined a significant improvement of phenolic compounds in all the three Italian cultivar EVOOs analyzed, whereas the volatile compounds showed a variability largely affected by the genetic origin of the olives with C6 aldehydes that seem to be more stable than C6 alcohols and esters.