Monounsaturated fats are the most beneficial to health, and of the dietary oils, olive oil is the richest source. Specifically, olive oil has up to 77% monounsaturated oleic and palmitoleic fatty acids, 14% saturated palmitic and stearic acids and 9% polyunsaturated linoleic and linolenic fatty acids.
The olive fruit is very high in oleuropein, an intensely bitter compound, and much less sugary than fellow drupes. While oleuropurin is safe, it is utterly unpalatable. Olives must be cured before they can be eaten whole. This is accomplished by soaking or packing the olives in salt, salt water, water or lye. The curing process leeches the bitterness from the fruit and leaves a plump, firm fruit.