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

• Published in: Food chemistry 2012-10, Vol.134 (3), p.1542-1548
• Main Authors: Fadda, C., Del Caro, A., Sanguinetti, A.M., Urgeghe, P.P., Vacca, V., Arca, P.P., Piga, A.
• Format: Article
• Language: English
• Subjects: Activity; Antioxidants - chemistry; Biological and medical sciences; Extra virgin olive oil; Fat industries; Food engineering; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; Olive Oil - chemistry; Plant Oils - chemistry; Polyphenols; Quality; Radical scavenging activity
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2012.03.076

► Effect of two extraction technologies and storage on quality of extra virgin olive oils. ► Changes in quality parameters were monitored for 18months of storage at 20°C. ► Legal quality indices changed moderately and shelf life was at least 18months under the storage conditions used. ► The low oxidative stress technology resulted in better oils. ► Radical-scavenging activity did not change over time and was due to the total polyphenols. Extraction technology has a great effect on quality of olive oils. This paper studied 18months 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.