Comparison of olive oil from Portuguese cultivar Galega Vulgar with two different methods of oil extraction

Abstract

Olive oil production is one of the important agricultural activities on the Mediterranean region and has a real impact on local economies. The objective of this work was the study of extraction methods impact on olive oil final quality. The variety studied is one of the varieties allowed for olive oil with Protected Origin Denomination (DOP) production in Alentejo. The Portuguese variety extracted was Galega Vulgar (Olea europaea L. subsp. europaea), harvested in the region of Elvas during the harvest of 2001 through 2004. An hydraulical press was used (discontinuous extraction method, Vieirinox, Portugal); and a two phases centrifuge "decanter" (continuous extraction method, Oliomio, Italy).

For olives maturation index, fat (NMR) content and plagues were determined. For olive oisl besides routine chemical analyses a Sensorial analysis and an electronic aroma analysis were performed (Alpha Mos Fox 3000). Preliminary results show significant differences among some of the parameters analyzed in the case of olive oils. Of all the parameters where significant differences were detected only acidity shows enough differences to classify the oil in other category according to EC regulation N.º 1989/2003 of 6 of November.

Similar studies are important to allow technological improvements in order to increase efficiency.