Characterization of monovarietal virgin olive oils from six crossing varieties

Volatile composition of virgin olive oil (VOO) from six Tunisian new cultivars was evaluated using headspace solid-phase microextraction method coupled to GC-MS and GC-FID. Various chemical classes were identified such as aldehydes, alcohols, esters, ketones, terpenes and carboxylic acids. The results showed that the most important contributors to olive oil aroma are C-6 aldehydes. These compounds are biogenerated from polyunsaturated fatty acids through the lipoxygenase pathway. Furthermore, they pointed out the predominance of the linolenic acid oxidation over linoleic acid one. The main volatile compounds present in the oil samples were C-6 derivatives such as (E)-hex-2-enal, (E)-hex-2-enol and hexanol. In addition to C-6 compounds, the aroma of the studied VOOs contains reasonable amounts of various classes of C-5 components. The tested oil samples showed different volatile profiles. Some components seem to occur exclusively in a specific oil samples and, consequently, their presence might be initially used to establish compositional differences. All results put in evidence that olive oil aroma compounds accumulate differently according to the cultivar. (c) 2007 Elsevier B.V. All rights reserved.