Equally important information result from further analyzes concerning the purity of olive oil. Also, specification of certain parameters such as volatile halogenated solvents, polycyclic aromatic hydrocarbons, etc. demonstrates possible environmental contamination of olive oil or olive-pomace oil.
| OIL PURITY VERIFICATION | |
|---|---|
| Humidity (KARL FISCHER method) | High moisture amount suggests wrong method application during oil extraction and export |
| Humidity & volatile at 105 °C | |
| Foreign substances insoluble in petroleum ether | High level of impurity suggests applying wrong practices during oil extraction and export of oil |
| Halogenated volatile solvents | Contamination of olive oil with various toxic substances |
| Fatty acids – trans fatty acids | Indication of the presence of refined oil in virgin olive oil |
| 2-monopalmitine | Indicates presence esterified (“synthetic”) oils |
| Triglyceride composition (by ECN) | Indication of possible tallow presence |
| D ECN42 | Indication presence of seed oils |
| Wax | Indication presence of pomace |
| Alkylkesteron | Low rate alkylkesteron denotes fresh, good quality olive oil |
| Sterols – Erythrodiol – Uvaol | Indication of possible pomace presence |
| Aliphatic alcohols | Indication of pomace presence |
| Sterols & aliphatic alcohols | |
| 3,5 – stigmastadienes | Indication of the presence of refined oil in virgin olive oil |
| 1,2 – diglyceride | High rate of this parameter denotes fresh, good quality olive oil |
| Pyropheophytin | Low rate of this parameter denotes fresh, good quality olive oil |
| alpha tocopherol (vitamin E) | Component with high biological value and high antioxidant properties |
| Total polyphenols | High rate suggests protection against rancidity and greater durability |
| Mineral oils | Impurity indicator |