Olive oil quality, purity and safety
Descriptions on the labels and definitions of olive oil is obligatory, used in trade in and out of EU, as long as they are in accordance with international compulsory rules (Commerce International Olive Council Standard IOOC, Alimentarius Codex).
According to Article 4§2 and Annex I of Regulation 865/04, in the retail stage only oils of the following quality classes may become available:
- Extra Virgin Olive Oil
- Virgin Olive Oil
- Olive Oil– composed of refined olive oils and virgin olive oils
- Pomace
Classification of olive oil in one of these categories is made after determining three basic parameters: the acidity, K constants and the number of peroxides. Wherever trading of olive oil, it is obligatory to indicate the category to which it belongs, and parameter values.
| BASIC QUALITY CONTROL PARAMETERS | |
|---|---|
| Acidity (%) | High acidity indicates that the oil is plagued by diseases of the olive fruit, hydrolysis or oxidation |
| Constants K270–K232–DK | Criteria distinguishing oil of poor quality or doped with another refined olive oil |
| Peroxides | High peroxides indicates oxidative deterioration and short durability |
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 |
| Oil safety criteria | Οil contamination with substances og varying toxicity degree |
|---|---|
| Pesticide residue control (450 active substances) | Contamination due to air & waterborne substance residues used as plant protection for growing olives or other neighboring cultivations. |
| Pesticide residue control (200 active substances) | |
| Pesticide residue control (50 active substances) | |
| Benzo–pyrene | Contamination index from combustion processes that have occurred near olive trees or mills |
| Phthalates (plasticizers) | Contamination due to improper oil contact with unsuitable plastic hoses or plastic tanks and containers |
| Heavy metals (iron, copper, lead, arsenic, nickel, cadmium) | Contamination may be due to mechanical equipment and water used in the extraction of olive oil |
| Ηalogenated solvents | This type of contamination may occur in all stages of oil processing and packing |