West Bank Olive Oil: Effect of Methods of Extraction on Its Physico-Chemical Properties

摘要

Olive oil production is a very important economic activity in the West Bank, but is threatened by cheap imports of Spanish olive oil and vegetable oil. This study identifies the major factors which affect oil quality in the West Bank and proposes a classification based on criteria of quality and purity. One hundred eighty seven samples were collected from all different types of mills, automatic, semi-automatic, hammer crusher and stone crusher. Percent acidity as % of free oleic acid, peroxide value, refractive index, optical rotation were determined, among others. The study found that West Bank olive oil is within the norms of the International Standards, so the standards should be enforced to prevent adulteration. Good quality oil may be changed by harvesting immature olives; improper harvesting, handling, and storage of olives; improper pressing, e.g., using old unmaintained mills and improper use of semi-automatic and automatic mills; improper collection and storage of oil. Without making a classification and enforcing it, West Bank olive oil can never compete against cheap imports of refined olive oil and vegetable oil. This is easy to do and should be done.