ABSTRACT
The olive is a drupe, like all stoned fruits and consists of three parts: epicarp, mesocarp, and endocarp. The skin or peel is covered with a continuous well-developed multilayer cuticle made of long-chain fatty acids together with aromatic compounds. Olive oil is obtained from olive fruit by mechanical procedures. Olive oil production involves one of the following extraction processes: discontinuous process in traditional mills, three-phase centrifugal olive oil extraction, and two-phase centrifugal olive oil extraction. Wastes and by-products generated during the olive oil production process are an important source of nutritionally valuable compounds including polyphenols, tocopherols, phytosterols, squalene, pigments—chlorophylls and carotenoids, volatile and aromatic compounds as well as protein, pectin, hemicelluloses, and lignin. The concentration of phenolic compounds in olive mill wastewater varies greatly from 0.5 to 24 g/L. Phenols can exist inherently in the olive fruit or be generated during olive oil production.
