The bitter taste is one of the positive sensory attributes of native olive oil obtained from fresh olives. This parameter is mostly due to the total phenol content, which depends on many factors, such as processing, maturity degree, variety, etc. However, an excessive intensity of the bitter taste in some virgin olive oils leads to rejection by costumers in some countries.

Ana C. Sánchez-Gimeno, Universidad de Zaragoza, Spain, and colleagues established a liquid-liquid extraction process using water as a solvent to decrease the total phenol content of olive oil, as some olive oil phenols are hydrophilic and therefore more soluble in water than in the oil phase. Efficient mixing of the two phases is accomplished by flowing nitrogen, which also avoids any oxidation of the oil.

Different oil-to-water ratios were examined, and the team found that a lower percentage of the oil is more efficient for phenol extraction. Other physical or chemical parameters of the olive oil are not changed by the liquid-liquid extraction and the taste is not negetively affected.

• Debittering olive oil by liquid-liquid extraction: Kinetics and the effect on the quality of arbequina olive oil,
  M. Abenoza, J. Raso, R. Oria, A.C. Sánchez-Gimeno,
  Eur. J. Lipid Sci. Technol. 2015.
  DOI: 10.1002/ejlt.201500215