Changes during storage of quality parameters and in vitro antioxidant activity of extra virgin monovarietal oils obtained with two extraction technologies

Extraction technology has a great effect on quality of olive oils. This paper studied 18 months of storage of
two Sardinian extra virgin monovarietal oils obtained with a traditional and with a low oxidative stress
technology. Oil samples were subjected to the following chemical analyses: acidity, peroxide value, ultraviolet
light absorption K232 and K270, carotenoids, chlorophylls, tocopherols and total polyphenols. The
antioxidant capacity of oils, polyphenol extract and oil extract (remaining after polyphenol extraction)
was also determined as radical scavenging activity. The results show that both extraction technologies
resulted in minor changes in legal and quality indices during storage, due surely to the high quality of
the oils as well as to the very good storage conditions used. Oils obtained with the low oxidative stress
technology showed lower peroxide value and acidity and resulted in up to 103% higher total polyphenol
content as well as increased radical-scavenging activity, with respect to oils obtained with the traditional
technology.