OLIVES - 101
Olives are the rock stars of Mediterranean cuisine - providing us with heart-healthy fat from their juices, and delicious and nutritious flavor from their fruits. Olives are loaded with phyto(plant)nutrients naturally, and depending on the variety, stage of maturity and post-harvest processing, nutrient content shifts.
The use of olive oil and olives in a Mediterranean diet has been linked to improved outcomes in weight control, reduction in diabetes risk, and improvement of cholesterol and triglyceride profiles. In addition, the biophenols in olives help reduce blood pressure and plaque formation in arteries. Olives are also a great source of copper, iron, dietary fiber and vitamin E.
Olives contain compounds called phenols and terpenes - phenols are antioxidants, protecting DNA in our cells from free radicals, and terpenes have been shown in some animal models to have anti-cancer activity.
Olives also contain anti-inflammatory properties - specifically, oleacanthal mimics the action of non-steroidal anti-inflammatory medications like ibuprofen, and olive oil added to the diet of those suffering from arthritis often improves pain management.
Unfortunately, the phytonutrients of olives are altered with processing and curing, so each oil and each fruit may have a different nutritional profile. The answer: eat lots of varieties, regularly!
Although savory, olives are officially a fruit - in fact, a special variety called a drupe. Drupes are more familiar to us as stone or pitted fruits - like mangos, cherries, peaches, plums, etc. But olives, and even almonds and pistachios, are drupes too.
Hundreds of varieties of olives exist, and they are all linked botanically with the designation Olea europea. Although they mostly thrive in Italy, Greece and Spain, they can be founds in different parts of Asia and Africa. Olive trees are extremely tenacious, with the oldest recorded tree standing after 2000 years! Evidence of olive tree existence date back almost 8000 years, but it took a while for olives to make their way to our shores - it's estimated that occurred in the 1500-1700's. There are over 25 million acres of olive trees worldwide, with Spain being the largest producer, followed by Italy and Greece. That's 800 million trees, people!
What's fascinating is that 90% of olives harvested are used for oil, and only 10% for consumption. And unlike other drupes, you can't just casually pick and olive and consume it. Olives contain a high concentration of oleuropein, a very bitter phytonutrient. So for olives to be palatable, they must be cured - either in water, brine, salt or lye.
Water curing is just that - soaking olives for weeks at a time in water. This method still leaves olives that are bitter tasting, as water can't extract the oleuropein very efficiently.
Brine curing involves soaking olives for months in a highly concentrated salt solution. Because this process is so lengthy, the olives undergo some fermentation, releasing lactic and/or acetic acids, which then allow the migration of the oleuropein into the brine. This results in a sweeter, less bitter olive. Typically Greek and Sicilian olives are cured this way.
Dry or salt-curing involves covering olives directly in salt, and used for olives that will be stored for a long time. Dry cured olives typically undergo some shrinkage and have wrinkly skins and intense flavor. Dry cured olives may subsequently be stored in red wine vinegar or olive oil to continue their preservation and add flavor.
Lye-curing involves soaking olive in an alkali solution of sodium hydroxide (NaOH for you chemistry fans) often up to 4-5 times to eventually cure the olive from the outside, through the flesh and down to the pit. Dark style and green olives are good examples. This is a faster process and helps get commercial olives out to market quickly. Part of this process may involve bubbling oxygen into the solution at the latter part of curing to darken the olives to a homogenous black color (the notorious Thanksgiving olives-on-the-fingers are good examples).
Lastly, if you are shopping in your local market's olive bar, make sure you go to one with high turnover, so the olives, and their fillings, are fresh. Avoid olives with bruising or soft spots, and make sure that all the olives you see are generously submerged in brine. Try a few pieces of several varieties, and enjoy the round the world experience! Remember, these little gems are good for you, good for your heart, and good on pizza!
Below are a few typical varieties you may see at your market or deli. Enjoy!