Frost of the olives on the tree due to temperature drops can produce sensory defects in virgin olive oil.
Temperature changes can be abrupt with freeze-thaw cycles or gradual and produce sensory and chemical changes in the oil.
A study by the Institute de la Grasa analyzed the qualitative parameters (free fatty acids, peroxide value, UV absorption and ethyl esters of fatty acids) and the phenols of the oil described with the sensory defect “frost-affected olives”.
The phenolic profiles have allowed these extra virgin olive oils to be grouped into two types.
One of these, characterized by “soapy” and “strawberry” aroma descriptors, had higher values of 1-acetoxypinoresinol, pinoresinol and the aldehyde form of the aglycone ligstroside.
The other, characterized by the descriptors “wood” and “humidity,” had higher concentrations of luteolin and apigenin.
The majority of oils (75%) in the first group, associated with sharp drops in temperature, have phenol concentrations higher than the value established by the olive oil polyphenol health claim approved by the European Commission.
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