Detailed Product Description
The target quality criteria are measured by laboratory methods. The main parameters used are:
- Acidity: This parameter evaluates certain alterations undergone in the oil. The higher the acidity level is the lower is the oils quality and digestibility.
If it exceeds 2° the oil must be refined. Extra virgin oil cannot exceed 0,8° (oleic acid)
- Peroxide index: This detects the incipient oxidisation. Oxidisations leads to the oil going rancid. The index also gives information about alterations in the tocopherols and polyphenols, which are the oil's natural antioxidants.
For extra virgin oil the peroxide index must not exceed 20 meq O2 /kg
- K-232 y K-270: These criteria complement the information obtained from the peroxide index as well as measuring purity. The K-270 value is increased if there are fatty acids present which are different to olive fatty acids.
For extra virgin oil the K-232 value cannot exceed 2.40 and the K-270 value 0.2
- Wax content: Proves the genuinity of extra virgin olive oil. The wax content of extra virgin olive oil must not exceed 250 mg per Kg of oil.
Approx. 99% of the weight of extra virgin olive oil is made up of Triglycerides (a combination of glycerin and fatty acids) and other free fatty acids.
Extra virgin olive oil is characterised by the fatty acids that make up the combination in the triglycerides. Fatty acids of particular importance here are:
Monoinsaturated Fatty Acids: Palmitoleic Acid (C16:1) 0.3 - 3%, Oleic Acid (C18:1) 61 - 83% Total amount monoinsaturated fatty acids 61.3 - 86%
Polyinsaturated Fatty Acids: Linoleic Acid (C18:2) 2 - 18%, Linolenic Acid (C18:3) max 1.5%, Total amount polyinsaturated fatty acids 2 - 19.5%
Saturated Fatty Acids: Miristic Acid (C14:0) max. 0.05%, Palmitic Acid (C16:0) 7 - 18%, Esthearic Acid (C18:0) 0.5 - 5%, Araquic Acid (C20:0) max. 0.5%, Total amount of saturated fatty acids 7.5 - 23.5%
Aprox. 1% of the weight of extra virgin olive oil is made up of a great number of smaller components that are very important regarding the oil's quality and performance. These include:
- Carotenes: responsible for colour, and a vitamin A source. Oxidisable.
- Clorophylls: also responsible for colour. They oxidise easily in light however they are inoxidants in the dark.
- Tocopherols: source of vitamin E. Anti-oxidising agent.
- Estherols: participate in the intestine absorption of cholesterol.
- Polyphenols: responsible for flavour, being the main defensive agents against the oxidisation of the oil.
- Volatile components: responsible for the aromas, of particular note are the alcohols, cetones, esthers, etc.