The ability of olive endogenous enzymes b-glucosidase, polyphenol oxidase (PPO) and peroxidase (POX),
to determine the phenolic profile of virgin olive oil was investigated. Olives used for oil production were
stored for one month at 20 ?C and 4 ?C and their phenolic content and enzymatic activities were com-
pared to those of ripening olive fruits. Phenolic and volatile profiles of the corresponding oils were also
analysed. Oils obtained from fruits stored at 4 ?C show similar characteristics to that of freshly harvested
fruits. However, the oils obtained from fruits stored at 20 ?C presented the lowest phenolic content.
Concerning the enzymatic activities, results show that the b-glucosidase enzyme is the key enzyme
responsible for the determination of virgin olive oil phenolic profile as the decrease in this enzyme activ-
ity after 3 weeks of storage at 20 ?C was parallel to a dramatic decrease in the phenolic content of the oils.