Lecture 6: Effects on olive oil quality

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C. Olive oil Quality1. Olive oil composition and
quality

• 6. Factors affecting olive oil quality

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Factors affecting olive oil quality

• olive varieties
• region of origin
• soil and weather conditions
• harvest period
• olive storage conditions
• processing conditions at the oil mill
• olive oil storage conditions

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Olive varieties

• different olive varieties produce oils of
  varying intensity
• from very mild to very bitter and pungent, with
  infinite variations in flavor and aroma, yield,
  antioxidant content, shelf life, and color

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Region of origin and olive oil

• the composition of oil is in large measure
  attributed to the agronomic or geographical
  origin. Certain zones are renowned for the
  characteristics of their oils
• in order to certify the origin zone of typical
  oils with excellent characteristics European
  Union defines the PDO (Protected Designation of
  Origin) and PGI, Protected Geographical
  Indication)

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PDO olive oil (part I)

• Protected Designation of Origin (PDO) is a
  European Union definition
• PDO products are most closely linked to the
  concept of terroir a sense of place discernible
  in the flavor of the food

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PDO olive oil (part II)

• PDO products must be produced, processed and
  prepared in a specific region using traditional
  production methods
• the raw materials must also be from the defined
  area whose name the product bears
• the quality or characteristics of the product
  must be due essentially or exclusively to its
  place or origin, i.e., climate, the nature of the
  soil and local know-how

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PGI olive oil

• PGI is slightly less stringent than PDO, the
  product must be produced in the geographical
  region whose name it bears
• the geographical link must occur in at least one
  stage of production, processing or preparation
• the region can focus on a specific quality,
  reputation or other characteristic attributable
  to that geographical origin

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Soil and weather conditions (part I)

• the sloping and hilly terrain results in an
  intense and prolonged exposure to the sun even
  in the winter time that favours the excellent
  lighting of the olive trees
• the very close distance between the olive groves
  and the sea, provides a constant ventilation
  (warm sea breeze) to the olive trees

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Soil and weather conditions (part II)

• this consists of an additional factor that
  contributes to the high performance and quality
  of the olive fruit resulting in the production of
  an absolutely genuine and pure extra virgin olive
  oil

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Harvest period

• the weather at the time of harvest is of great
  importance, and experienced farmers know when
  its the right moment to start
• its impossible to pick olives in rain, wind or
  fog for many reasons
• wind, rain and moisture can cause the olives to
  spoil in their crates before they are taken to
  the mill, for pressing

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Olive Storage Conditions (part I)

• It is undeniable that the transport method
  affects olive oil quality. Airtight plastic bags
  for storing olives should be avoided since they
  do not allow a sufficient amount of air in the
  bag, they increase olives temperature, they
  favour mold growth and have negative effects on
  olive and olive oil quality in general.

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Olive Storage Conditions (part II)

• Storage time and conditions also play an
  important role in olive and olive oil quality
• Storage time affects the basic phenolic compounds
  in olive oil

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Olive oil storage conditions

• olive oil storage before and after bottling is
  another vital factor
• stainless steel tanks and dark bottles prevent
  the oxidative degradation of the product due to
  being exposed to sunlight
•  the best temperature to store olive oil is below
  180C

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Change in the composition of olive oil with time
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Summary of 6th Lecture

• Factors affecting olive oil quality
• olive varieties
• region of origin
• soil and weather conditions
• harvest period
• olive and olive oil storage conditions
• processing conditions at the oil mill