No abstract

Modifications of virgin olive oil subjected to accelerated storage were evaluated by HS-SPME analysis. To find a suitable marker of oxidative degradation, the volatile compounds showing variable concentration during the oxidative process have been identified and quantified by SPME coupled to GC-MS and GC-FID, respectively. The SPME analysis results were then compared with the parameters usually applied to assess the oxidative status of lipids, such as peroxide value, spectrophotometric absorbance, and loss of unsaturated fatty acids. Finally, the assessment of nonanal has been suggested as a marker of oxidative degradation. This rapid, inexpensive, and reliable method may allow screening of oils prior to testing by a panel of assessors.

SPME was employed to characterize the volatile profile of virgin olive oils produced in two geographical areas of northern Italy: the region of the Gulf of Trieste and the area near Lake Garda. There are as yet no data on the headspace composition of virgin olive oils from these regions, characterized by particular conditions of growth for Olea europaea. Using the SPME technique coupled to GC-MS and GC-FID, the volatile components of 42 industrially produced virgin olive oil samples were identified and the principal compounds quantitatively analyzed. Significant differences in the proportion of volatile constituents from oils of different varieties and geographical origins were detected. The results suggest that besides the genetic factor, environmental conditions influence the volatile formation.