Quoted from    Medium.com

Understanding High Phenolic EVOO

What are phenolic compounds?

These are the organic compounds that are the by-products of plant synthesis and are known as phytochemicals. Polyphenols are regarded for their health promoting properties and occur in fruits, vegetables, whole grains, nuts, seeds and legumes, beverages (coffee, tea and wine), fats (olive oil) as well as spices and seasonings

However, there are phenolic compounds unique to olive oil that only occur during the malaxation process (crushing olives to release juice). There are 36 known phenolic compounds in olive oil. The two most widely researched for their health protective benefits are oleocanthal and oleacein.

Phenolic compounds are found in significant concentrations in certain olive varieties when harvested at a very specific time of the year. These olive oils are also sometimes referred to as early harvest. Agricultural methods, weather patterns, soil, drainage, harvest time and milling process, storage, and bottling methods affect the phenolic content.

Phenolic compounds, in particular oleocanthal, and oleacein are known for their anti-inflammatory and antioxidant properties. In vitro trials and an increasing number of human trials are studying the potential benefits of high phenolic olive oil in alleviating symptoms and potential therapeutic effect for Alzheimer’s, Rheumatoid Arthritis, Type II Diabetes, Leukemia and many cancers as well as other autoimmune and neurodegenerative diseases that are prevalent in today’s culture.

The presence of oleocanthal is indicated by the peppery effect on the back of the throat sometimes causing a cough reflex. Oleacein is known by the bitterness on the tongue. For people accustomed to purchasing olive oils awarded for flavour and aromatic character or a mellow olive oil, these characteristics of pepperiness and bitterness are often mistaken as a flaw in the olive oil.