Effect of Pressing Techniques on Olive Oil Quality
Different techniques of oil extraction are applied in Jordan, including traditional press, two- and three-phase systems. Results of the study indicated that there is a significant difference in olive oil quality obtained from different pressing systems in terms of free acidity, ultraviolet absorption, peroxide value, polyphenol content, organoleptic assessment and overall quality index. Olive oils obtained from the two-phase mills were classified as extra virgin olive oil. While, olive oils obtained from the three-phase mill were ranged from extra to ordinary virgin olive oil. In the contrary olive oils obtained from the three conventional mills were classified as lampante virgin olive oil. The two-phase decanters produce high quality olive oils with higher contents of total polyphenols which makes them more resistant to oxidation during storage. These decanters, also having an advantage of saving on wastewater disposal costs because they produce only a small amount of such waste.