The measurement of oil and moisture in olives gives information that may be used to increase output by growing high-oil-yielding olive types, harvesting the crop at the right time, and optimizing the oil extraction process.
Both the Olive Producers and the Olive Processors benefit from being able to perform rapid online or at-line measurements of these constituents because farmers typically receive payment based on moisture and oil content rather than merely weight.
Olive Oil Extraction Process
There are several processes at work when it comes to the extraction of olive oil. Hydraulic presses and decanter centrifugation procedures are two of the most classic technologies. The latter entails pulverizing the olives and stones into a fine paste, which is then malaxed (beaten) to break up the oil/water emulsion and induce bigger oil droplets to form.
Water is added to the paste before it is pumped into a huge horizontal centrifuge/decanter and spun rapidly. This leads the phases to separate into a solid fraction known as pomace based on their varied densities (an oil, and vegetable water faction). After that, the two liquid fractions are centrifuged at even greater speeds to separate the remaining water and oil.
Measurement Location
There are several possible measuring locations:
- On the paste as it passes into the decanter/centrifuge
- On the pomace that is piped out of the centrifuge/decanter containing a window for viewing
- On the pomace in the screw conveyor
At-line measurement is also possible using a SpectraStar™ XT Series or Process Sensors QuikCheck unit that monitors the moisture and oil content of the samples in real-time.
Measurement Performance
Source: KPM Analytics
Location |
Range |
Pre Decanter Accuracy |
Post Decanter Accuracy |
Moisture |
40-70% |
0.9% |
1.2% |
Oil |
15-35% |
0.6% |
0.3% |

Image Credit: KPM Analytics

Image Credit: KPM Analytics

Image Credit: KPM Analytics

Image Credit: KPM Analytics

This information has been sourced, reviewed and adapted from materials provided by KPM Analytics.
For more information on this source, please visit KPM Analytics.