Proceedings of the XLVII Italian Society of Agricultural Genetics - SIGA Annual Congress

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Poster Abstract - 5.44

MOLECULAR MARKER CHARACTERISATION OF OLIVE OIL VARIETY COMPOSITION

L. Palmieri*, S. Doveri**, N. Marmiroli*, P. Donini**

*) Dept of Environmental Science University of Parma, Parco Area delle Scienze 11/a, 43100 Parma, Italy

**) NIAB Huntingdon Road CB3 0LE Cambridge - UK

Olea europaea, olive oil, SSR, SNP, RealTime PCR, traceability

Olive (Olea europaea) is the most important oil-producing crop in the Mediterranean. Its cultivation is expanding due to the increase in oil demand following dietary trends and perceived health benefits. The quality and market value of olive oils are defined by several parameters, ranging from the chemical composition to the nutritional and organoleptic properties, to the area of olive production which is often associated to specific varieties, and to the industrial processing of oil. An expanding market for a high value agricultural product is exerting a pull for novel methods that could be used for quality assurance, for assisting trade of raw and finished products, and for the protection of brands. Research focussed on the authenticity and provenance of agricultural products has recently received the attention of both the EU and National programmes. While the chemical analysis of olive oils allows the assessment of most quality parameters such as fatty acid composition¹, triglyceride composition², sterol composition³ and general chemical composition⁴, it is largely unsuitable for the determination of variety composition.

We report on the variety molecular identity characterisations of DNA from both olive tissues and olive oil. Our studies are progressing in the frame of two FPV EU-funded projects (DNA-TRACK and OLIV-TRACK), and with the support of the UK Food Standards Agency.

In order to pursue the molecular determination of oil PDO, DOC and variety authenticity, we have been facing several technical challenges, starting from the development of methods that would allow the isolation of good quality DNA from olive oil.

Our study has progressed on the genetic identity characterisation of olive oil varietal composition using microsatellite markers (SSR), and on the quantification of the relative proportion of different varieties entering the composition of oil blends.

We have determined that amplifiable DNA is recoverable from filtered and unfiltered olive oil and that SSR markers are suitable to distinguish between different varieties. Moreover we are developing a set of SNP markers from functional genes that will be used to quantify genotypes within oil blends using fluorescent probes in Real Time PCR. In addition the SNP markers will be employed in the study of genetic diversity in functional genes involved in fatty acid biosynthesis pathways. Our research is thus resulting in the production of advanced technical protocols for commercial diagnostic testing, in the production of markers, and in basic scientific knowledge on the genetic diversity of olive and in the study of functional diversity at specific loci.

References:

1) Stefanoudaki E. et al, Am Oil Chem Soc 76:623-626 (1999)

2) Stefanoudaki E. et al, Food Chem 60:425-432 (1997)

3) Leardi R. et al., Riv Ital Sost Grasse 64: 131-136 (1987)

4) Aparicio R. et al., Grasas Aceites 41(1):23-39 (1990)