EVOO Chemistry

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.