EVOO Chemistry

  • The major fatty acid in olive oil tryclyglycerols.
  • This monounsaturated fatty acid makes up 55 - 85% of olive oil.
  • Higher oleic acid content translates into increase durability and shelf life with greater resistance to oxidation.
  • Extra virgin olive oil is generally higher in oleic acid than other vegetable fats.


  • A low FFA is desirable.
  • Free fatty acid speaks to the condition of the fruit at the time of crush.
  • Higher FFA values are indicative of poor quality fruit such as damaged, overripe, insect infestation, high temperatures during extraction or too much time between harvest and crush.


  • The primary measurement for rancidity in oil
  • A very low peroxide value is desirable.
  • Peroxides are formed when oils are exposed to oxygen causing defective flavours and odours.
  • Higher values are indicative of poor quality and/or storage conditions.


  • The healthful antioxidant substances in olive oil which aid in slowing down the natural oxidative processes.
  • Phenolic content decreases over time or when exposed to heat, oxygen or light and is an indicator of freshness.
  • Polyphenols in extra virgin olive oil are connected with peppery bitterness and other desirable flavour characteristics.
  • Consuming fresh, well made olive oil with high polyphenol content is crucial when looking to obtain the maximum health benefit commonly associated with extra virgin olive oil


  • Low values can indicate oxidized oil & sensory defects.
  • A useful indicator of fruit quality and acts as a snapshot of olive oil freshness.
  • Used as a means to test for refining/deodorizing.
  • Also an indicator of the age of an oil


  • This test was developed to measure the degradation of chlorophyll in olive oil.
  • This degradation of chlorophylls to pyropheophytin was found to take place at a predictable pace, making it possible to gain information about the age of an olive oil.
  • The rate at which the degradation occurs can be accelerated by even short periods of high temperatures
  • A useful indicator of the presence of deodorized olive oils or soft column refining.