Phenolic composition and antimicrobial activity of Algerian olive products and by-products

This work characterized the phenolic profile of virgin olive oil, pomace, and olive mill wastewater (OMWW) of the three Algerian cultivars Blanquette, Rouguette and Sigoise, which were generated by traditional discontinuous press and 3-phase centrifugal extraction processes. Results revealed the cv. Blanquette as the cultivar with the highest phenolic content and no conclusive differences between the oil extraction processes were found. The antimicrobial activity exerted by OMWW and olive oils was attributed to their phenolic content, especially glutaraldehyde-like compounds. The most bactericidal OMWW, which presented the highest phenolic concentration (10,828 mg/L), showed a minimal bactericidal concentration (MBC) of 2.5% for all target microorganisms. In addition, a concentration of 452 mg/kg of total polyphenols in the olive oil reduced more than 3 log units from the initial inoculum in 30 min. Olive derived products showed a remarkable antimicrobial activity that makes them a good source of natural antimicrobials.