Chemistry Terms and Definitions

Throughout our website we use many technical and scientific terms to describe our olive oils and how they relate to various associated health benefits. Many of these terms are also used to emphasize their quality, for comparison purposes against various standards, and for you to make an educated decision when deciding what the best olive oils are for your own health.

Free Fatty Acids - FFA

Expressed as a percentage, this indicates the condition of the olives at time of crush! Healthy fruit, processed immediately should produce an olive oil with low FFA!  The lower, the better! An oil with a low (FFA) will have a higher smoke point than an oil with a higher FFA.  The IOC (International Olive Council) requires that this number be below 0.8 in order for an olive oil to be considered "Extra Virgin" grade. The UPTM (Ultra Premium) Standard takes this further and has a limit of 0.3.

Peroxide Value - PV

Expressed as milliequivalents (mEqO2/kg) - the peroxide value is defined as the amount of peroxide oxygen per 1 kilogram of fat or oil.This number must be equal to or less than 20. This is the primary measurement of the rancidity of a particular extra virgin olive oil. Peroxide value is affected by procedures used in processing and storing of the oil. Peroxide is responsible for color and aroma changes as the oil oxidizes. The UPTM (Ultra Premium) Standard takes this further and has a limit of 9.

Oleic Acid

Exressed as a percentage. A higher level is better! Oleic acid is responsible for some of the health benefits of EVOO, and its high resistance to free radicals helps to slow down the spread of damaging chemical chain-reactions. Because of its high degree of resistance to attack by oxygen free radicals, higher levels of oleic acid in an olive oil help keep it fresher for longer, by preventing the formation of peroxidized (rancid) fats.

Our bodies absorb any peroxidized fats that we consume and incorporate them into our cells. Oleic acid’s superior resistance to free radical attacks protects our cell membranes, proteins, and DNA from being damaged, as it protects the oil from spoiling.

Substituting oleic acid for saturated fatty acids in animal fats improves cholesterol balance, and research also suggests that oleic acid may have more specific health benefits, such as the ability to help regulate healthy blood pressure by altering cellular signaling. For these and other reasons, the US FDA has approved the health claim that “Limited and not conclusive scientific evidence suggests that eating about 2 tablespoons (23 grams) of olive oil daily may reduce the risk of coronary heart disease due to the monounsaturated fat in olive oil.” The IOC (International Olive Council) requires that this number be at least 55% for an olive oil to be considered "Extra Virgin" grade. The UPTM (Ultra Premium) Standard takes this further and has a minimum requirement of 65%.

Biophenols  Profile

As science developed, we have learned that a significant amount of health attributes related to extra virgin olive oil are not only linked to its profile rich in monounsaturated fatty acids but also to its biophenol content. In the early days, total biophenol content was simply measured by measuring the reaction of this complex group of substances with a colorant (Folin-Ciocalteau).

The darker the blue colour developed from the reaction, the higher the level of biophenols. The actual level of biophenols was determined by a comparative scale measuring how much colour was developed by known quantities of a standard phenol (either caffeic acid or garlic acid). Even when this method provided a reasonable indication, it was far from perfect as all different phenols react to the colorant in different ways. Furthermore, it did not tell us anything about the different groups of biophenols. As we know now, some of those biophenols have very specific health and sensory properties (i.e. Oleocanthal, which has important antinflammatory action and it is responsible for the pungent feeling on the back of the throat).

Even when there is no limit for polyphenols in international standards, they are very effective antioxidants in olive oil and contribute significantly to oxidative stability, shelf life and health claims. Given the growing importance of these antioxidants, a new and more precise measuring method has been developed. This method utilizes High Performance Liquid Chromatography (HPLC).

HPLC - High Performance Liquid Chromatography (HPLC) is a form of column chromatography that pumps a sample mixture or analyte (in this case EVOO) in a solvent (known as the mobile phase) at high pressure through a column with chromatographic packing material (stationary phase). The sample is carried by a moving carrier gas stream of helium or nitrogen. HPLC has the ability to separate, and identify compounds that are present in any sample that can be dissolved in a liquid in trace concentrations as low as parts per trillion. Sample retention time (the time that it takes for each biophenol to exit the column) will vary depending on the interaction between the stationary phase, the molecules being analyzed, and the solvent, or solvents used. As the sample passes through the column it interacts between the two phases at different rate, primarily due to different polarities in the analytes. Analytes that have the least amount of interaction with the stationary phase or the most amount of interaction with the mobile phase will exit the column faster. A detector at the point of exit determines when and how much of each biophenol is sensed. The total amount of biophenols in this method is determined by adding the individual quantities of each measured biophenol.

There are typically more than 30 different biophenols in extra virgin olive oil. The prevalent classes of hydrophilic phenols found in EVOO are phenolic alcohols and acids (i.e. Hydroxytyrosol and vanillic acid), flavonoids (i.e. luteonin), lignans (i.e. pinoresinol) and secoiridoids. Among these substances the last two classes include the most concentrated phenols of EVOO. Secoiridoids, like aglycone derivatives of oleuropein, demethyloleuropein and ligstroside, are present in olive fruit as most abundant EVOO phenolic antioxidants. Several important biological properties (antioxidant, anti-inflammatory, chemopreventive and anti-cancer) and the characteristic pungent and bitter tasty properties have been attributed to EVOO phenols.


Expressed in mg caffeic acid/kg  -  a ppm or parts per million value of mg caffeic acid/kg of oil. Antioxidant like substances that are naturally occurring in Extra Virgin Olive Oils. Phenols extend the shelf-life of extra virgin olive oil & also determine the “style” in terms of bitterness and pungency. Generally, when an oil has a high phenol count (presented in parts per million), it will have more “pepper” or more “bitterness”. Many consider phenols to be free-radical “scavengers”.

DAGs (Diacylglycerols)

Expressed as a percentage. DAGs are always reported & presented in the1,2 ratio (as a percentage of total DAGs) as the oil ages, the 1,2 DAGs are transformed to 1,3 DAGs

Fresh Olive Oil made from sound fruit should result in a DAG content of 85% or higher whereas the processing of rotten and or fermented olives will produce fresh oil with low DAGs indicating a very short shelf-life. DAGs typically drop between 20-30% per year depending on storage conditions and FFA. They are highly influenced by heat but not light. DAGs are important shelf-life indicators and can be used to determine the shelf life (or lack thereof) of an oil at any time in its life. Recent studies show that many grocery store oils fail DAGs (35% is considered failing in the voluntary Australian standard) which shows a high correlation with sensory defects, more so than any other test.

The degradation of DAGs (rate) are highly predictable over time if initial quality (FFA) is known and storage conditions.

(PPP) Pyropheophytins

​Measures the degradation of Chlorophyll in Olive Oil. Most sensitive method (ratio) able to detect the presence of deodorized (soft-column refined, thermally treated) oils. Recent studies show that many grocery store oils fail PPP (17% is considered failing in the voluntary Australian standard).

Freshly made oil should have a PPP of close to zero.

Soft column refining is generally used to strip out sensory defects  and otherwise neutralize some chemical parameters in old oils or oils made from over-ripe and fermented (late season) olives so that they can pass typical authenticity tests, undetected.

PPP are highly influenced by heat and then also by light. In ideal storage conditions, they should only increase between 6-8% per year! An oil with an extremely high PPP is a clear indication that “something” is wrong or amiss. Either the oil is severely aged, deodorized or has had continuous light exposure (clear packaging!) for extended time periods and/or higher than normal storage temperatures. 


Expressed in ppm - parts per million. A nutrient that the body needs in small amounts to stay healthy and work the way it should. It is fat-soluble (can dissolve in fats and oils) and is found in seeds, nuts, leafy green vegetables, and vegetable oils. Alpha-tocopherol boosts the immune system and helps keep blood clots from forming. It also helps prevent cell damage caused by free radicals (highly reactive chemicals). Alpha-tocopherol is being studied in the prevention and treatment of some types of cancer. It is a type of antioxidant. Also called vitamin E.


Expressed in ppm - parts per million. Squalene is a natural organic compound which is part of our tissues. It is a polyunsaturated hydrocarbon, its molecular structure resembles that of vitamin E. However Squalene contains four additional groups of isoprenoids, which are very potent natural antioxidants.  It is one of the many natural lipids our body produces to lubricate and protect our skin. Squalene is estimated to make up about 10 to 12 percent of our skin's oil.

More Terms and Definitions found on this site:


The Protected Designation of Origin mark, better known by the acronym P.D.O., is a mark for the legal protection of the name that the European Union attributes to those foodstuffs whose intrinsic quality characteristics are due essentially or exclusively to the geographical area in which they are produced. Also referred to as DOP - Denominazione di Origine Protetta in Italian. The designation is granted under a European Union quality scheme, and recognizes the fact that production is strongly linked to the territory of origin and, in particular, every part of production takes place within the specified region. 

The Consortium (of Modena)

In 2009, the “Consorzio Tutela Aceto Balsamico Tradizionale di Modena” (Traditional Balsamic Vinegar of Modena Protection Consortium) was appointed by the Italian Ministry of Agricultural, Food and Forestry Policies (MIPAAF), which represents Italy within the European Union in matters falling within its sphere of competence, to protect and promote “Aceto Balsamico Tradizionale di Modena” (Traditional Balsamic Vinegar of Modena). While Italy has 836 products with Designation of Origin and Geographical Indication quality marks, and is acknowledged as a truly unique country in terms of products of undisputed excellence, Traditional Balsamic Vinegar of Modena P.D.O. is undoubtedly a special case: it is a product that testifies not only to traditions whose origins are shrouded in the mists of time, but also to the unique Modenese passion, love for the land, patience and know-how. Protected Designation of Origin (P.D.O.) means that the vinegar’s entire production chain, from grape harvesting to ageing of the product, takes place strictly within the boundaries of the Province of Modena. In Modena, there are two official quality formats: "Affinato" - with a minimum age of 12 years, and the “Extravecchio" - with a minimum age of 25 years. Bottled only in the Giugiaro bottle, 100ml, it is the only official bottle for all producers in Modena. This unique bottle is in the shape of a spherical ampoule in solid, clear glass with a rectangular base, in a style reminiscent of the glass flasks used by tasters.

The Consortium (of Reggio Emilia)

Consorzio Tutela Aceto Balsamico Tradizionale di Reggio Emilia DOP - The Traditional Balsamic Vinegar of Reggio Emilia is sold in the typical small bottle containing 100ml. and having an overturned tulip-like shape and sealed on the plug with the sealing wax stamp of the Consortium (in order to guarantee the quality of the content) as well as with numbered labels with three different colours (lobster "red", silver, gold) differentiating the relevant qualities. The result of so much patience is a syrup-like liquid having a dark brown colour and a penetrating and inimitable bitter-sweet taste. Aragosta (lobster/red) label: minimum of 12 years. Silver label: minimum of 20 years. Gold label: minimum of 25 years.