Pateira

Sometimes, in a depreciative way, Portugal, Spain, Italy and Greece are called the European Olive Belt.  Well I do not find what mother-earth gives us depreciative at all. Quite the contrary!

The Portuguese olive oil is one of the best in the world.  Here are some important definitions:

Extra Virgin olive oil - It has an absolutely impeccable taste and aroma; fruity; the acidity, expressed in oleic acid, may not exceed 1%. Extra Virgin olive oil accounts for less than 10% of the Portuguese production.
Virgin olive oil - Perfect flavor and odor, maximum acidity (oleic acid) of 2g/100g - 2%.
Ordinary Virgin olive oil - Good flavor and odor, maximum acidity (oleic acid) of 3.3g/100g - 3.3%.
Lampante Virgin olive oil - Virgin olive oil with an acidity of more than 3.3%. Not fit for direct consumption.
Olive Oil - A low cost blend of refined and virgin oil. Maximum acidity (oleic acid) of 1.5g/100g - 1.5%. The cheap refined oil is mixed with a flavorful virgin oil.
Refined Olive oil or Pure olive oil  - This is obtained by refining virgin olive oils which have a high acidity level and/or organoleptic defects which are eliminated after refining.

In Portugal you can find "Olive Oil with Protected Origin Denomination"  (DOP).   The "DOP Olive Oils" like top wines, are originated in one specific geographical area, with unique soils and climat and made of special varieties of olives.   Portugal has five "DOP" areas for producing Olive Oil: 

• 
  "Moura", small area in Alentejo.
  "Trás-os-Montes" from North East of Portugal.
  "Beira Interior" from Center of Portugal. 
  "North Alentejo" and
  "Ribatejo". near Lisbon area. 
  

My advice to you would be a virtual visit to "Herdade do Esporão" or, better, a real tour to the state in the heart of Alentejo region, 180 Km south of Lisbon, in Reguengos de Monsaraz. With the bonus of tasting excellent wines... 

"Limited and not conclusive scientific evidence suggests that eating about two tablespoons (23 grams) of olive oil daily may reduce the risk of coronary heart disease due to the monounsaturated fat in olive oil. To achieve this possible benefit, olive oil is to replace a similar amount of saturated fat and not increase the total number of calories you eat in a day."

decision announced in November 1, 2004 by the American Food and Drug Administration.