Optimisation of olive oil extraction and minor compounds content of Tunisian olive oil using enzymatic formulations during malaxation

The aim of this work was to investigate and evaluate culture filtrates of different enzymatic formulations in terms of their individual and synergistic effects with regard to the quality and extraction yields of Tunisian olive oil from the Chemlali Sfax variety. The formulations, which contained a number of hydrolytic enzymes, particularly pectinases, xylanases and cellulases were tested both separately and in combination. The results demonstrated that when compared to those of the control, the oil extraction yields of both types of olives (green and black) treated by the enzymatic formulations were enhanced by 1.5%. Interestingly, the synergistic effect of different activities (pectinase, cellulase and xylanase) was able to improve the extraction of polyphenols to 10% and of pigment compounds, namely chlorophylls and carotenoids, by 25 and 30%, respectively. The olive oil stability, particularly the one from green olives, which was treated by the enzymatic mixture, was observed to increase up to 3.5 h. Overall, the findings presented in the current study demonstrate that the enzymatic formulations under investigation exhibited promising properties and attributes which make them potential strong candidates for future application in the oil industry. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.