Characterisation of Phenolic Compounds in Oils Produced from Frosted Olives

Frost is one of the most important weather related hazards for the Australian olive industry and it has caused significant economic losses during the last decade. Its impact on oil quality was significant in 2006 with more than 20% of Australian oil of that year being affected to some degree. Early frosts will normally affect the fruit leading to significant changes in the chemical and organoleptic characteristics of the oils. The aim of this work was to study the effect of freeze damage on the phenolic composition and quality parameters of oils from three different varieties: Frantoio, Barnea and Picual. Quality chemical parameters showed significant differences in oils produced from fruit that was frozen for 2 and 4 weeks. Those chemical parameters were not significantly different in the oil produced from fruit immediately after being frosted. Nonetheless, the sensorial profile and the polyphenols showed significant changes even with oils produced within a short time after the freezing event. Those changes became more evident with the oils produced at increasing time from the moment of fruit freezing.