Microbiological characterization of Picholine variety olives and analysis of olive oil produced in traditional oil mills in Morocco

Abstract

The physico-chemical and microbiological characteristics of olive oil can be affected by both storage time of the olives before milling, and also the manner in which the oil is stored.The aim of this study was to determine the microbiological profile of olives stored for different periods (7, 15 and 30 days) and to examine the olive oils obtained by measuring changes in physico-chemical and microbiological characteristics, including polyphenol contents and antioxidant capacity, after 3 and 6 months storage.In all olive samples, and also in all the corresponding oils, the main micro-organisms found were mesophilic and psychrotrophic bacteria, yeasts and moulds. Enterobacteriaceae were not detected. It was noted that storage produced a significant increase in acidity, peroxide contents and ultraviolet absorbance, as well caused a significant reduction in polyphenol contents and antioxidant capacity.