Olive oil extraction is an ancient practice that, over the years, has undergone significant innovations to improve both the quality of the final product and the efficiency of production processes. Among these innovations, the shift from three-phase extraction systems to two-phase systems has brought numerous benefits, both in terms of environmental impact and product quality. Let’s take a closer look at these two processes and the changes they have brought to the olive oil production industry.
The Three-Phase Decanter
Traditionally, olive oil extraction was carried out using a three-phase system, which separated the olive paste into three components: oil, vegetation water, and pomace. The process relies on a high-speed rotating drum that uses centrifugal force to divide these three components.
The three-phase system requires the addition of a significant amount of water (about 20% to 30% of the processed olive paste) to facilitate the separation. However, this addition poses a crucial disadvantage: the dilution of phenolic compounds, particularly polyphenols, which are responsible for many of the beneficial properties of olive oil, such as its bitter and pungent taste and its antioxidant capabilities.
Moreover, the use of added water generates large amounts of vegetation water, the disposal of which represents a cost and an ecological challenge for producers. Although the three-phase system is stable and reliable, these drawbacks have led to the development of alternative technologies.
The Two-Phase Decanter
In response to the limitations of the three-phase system, the two-phase decanter was developed. In this system, the olive paste is separated into only two components: oil and wet pomace. The main advantage of this approach is that no water is added during the separation process.
The absence of added water offers several benefits. First, there is no production of vegetation water to be disposed of, as no water is used in the extraction, resulting in a positive impact on both operational costs and the environment. Additionally, due to the reduced use of water, the polyphenol content in the oil remains higher, ensuring a final product that is richer in nutritional and sensory qualities. Oil extracted using the two-phase system tends to be more bitter and pungent, qualities highly valued in premium markets.
However, the two-phase system requires greater attention and precision in managing the machine, as an imbalance in the process could lead to oil loss in the pomace, reducing production efficiency.
The Benefits of the Transition to Two-Phase Systems
The transition from a three-phase to a two-phase system has brought numerous benefits:
Final Product Quality: Oil obtained with the two-phase system tends to be richer in polyphenols, which give it a more intense organoleptic profile and improved antioxidant properties. These compounds are essential for the oil’s stability over time, preserving its freshness and quality.
Reduced Environmental Impact: The adoption of the two-phase system completely eliminates the use of water during the oil and pomace separation process, resulting in two significant advantages. First, there is considerable savings in potable water, approximately 2 liters for every liter of oil produced, a crucial factor in a time when water resources are increasingly scarce. Second, as no vegetation water is produced, there is no risk of environmental pollution related to the management of these wastewaters. This makes the process much more sustainable and environmentally friendly. Moreover, the resulting pomace is more concentrated and free of excess water, making it ideal for reuse for energy purposes. It can be used for the production of biomethane or transformed into combustible biomass, thus contributing to waste reduction and promoting a circular economy approach while simultaneously reducing the overall environmental impact.
Improved Production Efficiency: Although the two-phase system requires more careful management, the reduction of steps and byproducts leads to greater efficiency in the overall management of the production cycle.
Preservation of Sensory Properties: Recent studies have shown that oil extracted through the two-phase system retains its organoleptic characteristics for a longer period compared to oil extracted with the three-phase system, ensuring better preservation of taste and aroma.
Conclusions
The transition from three-phase to two-phase olive oil extraction systems represents a significant technological advancement in the olive growing sector. This change has allowed producers to improve oil quality, reduce environmental impact, and optimize operational costs without compromising the stability of the process. Oils obtained with the two-phase system are not only healthier due to their high polyphenol content but also richer in flavor, making them an ideal choice for quality-conscious consumers.
In addition to O.T.A., which implemented this process in its Cerbaia mill many years ago, all producers who have adopted this system have seen a notable improvement in the qualitative yield of their product, solidifying extra virgin olive oil as one of the symbols of Italian tradition and culinary excellence.
