A critical factor in the decanter’s performance is Dn, or the differential speed between the drum and the screw. The drum rotates at a high speed to generate centrifugal force, while the screw moves at a different speed to transport the solid residues (pomace) out of the decanter. The speed difference between these components directly impacts the efficiency of separation and the quality of the oil:
- Higher Dn (e.g. Dn16): A greater difference in speed leads to faster separation of the olive oil from the paste, reducing the oil’s exposure to oxidation. However, faster separation can result in less time for the extraction of phenolic compounds and other antioxidants from the paste.
- Lower Dn (e.g. Dn11): A smaller differential speed slows down the separation process, allowing for more thorough extraction of phenolic compounds but potentially increasing the risk of oxidation due to prolonged contact with oxygen and water.
Read more:
A Technical Overview For Optimising Extra Virgin Olive Oil Quality Through Decanter Settings