Olives

Olive (Olea europaea) is a small tree species belonging to the family Oleaceae, which is widely cultivated in many parts of the world, due to its multiple health benefits. The fruit of this tree is also known as olive that is the main ingredient in many cuisines.

The fruit of olive is smaller drupe, however, the great variation is observed in the fruit size of orchard cultivars and wild plants. The olives are being consumed as table food but a major portion of olives is converted to olive oil. Based on color, two main categories green and black olives are widely known.

In terms of nutritional value, there is no much difference between these two types. In the freshly picked green olives, the amount of sodium content is twice than in the black olives. The color of olives is dependent on the degree of ripening at the picking stages.

Generally, the picking of green olives is before ripening and harvesting of black olives is after ripening. The black is an indication that fruit is ripened. Freshly picked, raw olives are green color cannot be eaten fresh due to bitter taste. Due to very bitter taste, the olives cannot be eaten just after picking from the trees. The bitter taste of fresh and green olives is attributed to the presence of glucoside.

Despite the nature of plant and fruits, the compounds in the category of glucosides are all bitter but the glucoside of olive also known as oleuropein is most bitter among all other glucosides. Due to this reason, the raw olives are cured for eliminating the bitterness due to oleuropein.

Curing of Olives¶

Both fresh and ripened olives are cured and then packed in the water, salt or brine solution. As compare to the black olives, the green olives are more bitter, firmer, and denser. However, the texture and taste of olives are dependent on the preservation method and duration. The characteristic fruity taste of olives can be easily preserved in water or oil. Use of salt is a key feature for preservation as it removes the pungent bitterness and effectively unlocks the best and quality taste.

Before preserving the olives, rinse them well with water to remove any dust and remains of chemicals. A light smack can be given to the olives with the help of a wooden mallet so that some amount of water can penetrate inside the olives. At this step, it is extremely important to make sure that the fruit remains intact. If the appearance of olives is of more concern then one can simply slit them by using a knife. Generally, it is recommended to make three slits so that water can easily penetrate the fruit. After this step, the olives should be placed in any food-grade bin and should be properly covered with the help of lid.

Direct exposure to sunlight should be avoided. With each passing day, the water should be changed with cold and fresh water. Change of water is highly recommended to avoid bacterial growth. After 7-10 days one can check the level of bitterness and at the desired level, the soaking in water can be stopped.

For the preservation of olives in brine, the salt is mixed in water in a ratio of 1:10. A raw egg can be used for the determination of salt concentration in the solution. If the egg sinks instead of floating, then more salt should be added to that solution. The fresh olives and brine solution can be placed in the bucket. This bucket should be covered with a lid but should not be tightened. It will let the fermentation gasses to escape. Regular mixing and stirring of brine and olives should be often to activate the process of fermentation.

The 10% of salt concentration should be maintained throughout the process, otherwise, the spoilage may occur. Instead of brine solution, the olives can also be cured in the oil, but the pre-treatment and maintenance of salt is the same requirement for both processes. Sometimes olives are stuffed with other materials to enhance the value of food and taste. For filling of the olives, onion, feta cheese, almonds, tomatoes, cloves, salts, papers, cumin, butter, and cheese are used.

Cultivation of Olives in World¶

The best quality of olives is being grown in California (Mission, and Arbequina varieties), Spain (Cornibranca and picual), Portugal (Cordovil, Cobrançosa, and Galega varieties), Italy (Leccino, and Frantoio varieties), Turkey (Memeili, and Gemik varieties), Greece Halkidiki, Kalamon, and Korononeiki varieties), Argentina (Coratina, Frantoio, Arbequina, Arauco varieties), and Chile (Arbequina, Picual, and Frantoio varieties).

The flavor profile of olive is different in each area and their processing is done according to the taste preferences of local people. Larger and freshly harvested olives are best for curing purposes, whereas, the olives having less flesh are best suited for the production of olive oil.

Nutritional Value of Olives and its Impact on Human Health¶

Consumption of olives offers wonderful health punch. Olives are significantly important for the normal activities of heart and blood circulation. The composition of olives offers a good amount of monounsaturated fatty acids which are well known for reducing the amount of bad cholesterol while maintaining an optimum amount of good cholesterol. The polyphenols in olives are powerful antioxidants which cause protection against chronic inflammation and oxidative stress. Polyphenols are also known to improve the mineral density of bones. Olives also contain significant amounts of vitamin E that is a powerful antioxidant and causes improved cognition. Black olives are good sources of vitamin A that are essential for the health of eyes.

Due to a reduction in oxidative stresses and protection of cellular DNA, the risk of suffering from certain cancers is also used. The antioxidants and mono-saturated fats in olives are highly beneficial for lowering the risk of type II diabetics. Many studies have reported that the use of olive oil greatly reduces the risk of cardio muscular mortality. The compounds in olives are capable to increase the production of nitric oxide thereby improving the vascular functions, and promote the proper flow of blood to body tissues. Additionally, olives are a good source of iron that is an essential element for the proper delivery of oxygen to body organs. Eating olives is also recommended to achieve weight loss goals.