Olive & Oil 15/11/2014

Monitoring endogenous enzymes during olive fruit ripening and storage

Similar phenolic profiles of the oils extracted from fruits stored at 4 °C and fresh harvested ones were found. C6 volatile compounds increased during ripening while a decrease was noted in oils extracted from fruits stored at 20 °C

The ability of olive endogenous enzymes β-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 compared to those of ripening olive fruits.

Phenolic and volatile profiles of the corresponding oils were also analyzed.

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 β-glucosidase enzyme is the key enzyme responsible for the determination of virgin olive oil phenolic profile as the decrease in this enzyme activity after 3 weeks of storage at 20 °C was parallel to a dramatic decrease in the phenolic content of the oils.

di R. T.