DNA extraction from olive oil and its use in the identification of the production cultivar

DNA recovery from food samples might be of great importance when the raw material used in the production process has to be traced. We were interested in verifying the presence of nucleic acids in extra virgin olive oil in order to determine the cultivar of origin of the olives used for the production. A reliable DNA extraction method for extra virgin olive oil has been defined, as far as both quantity and quality are concerned, and the possibility of using this DNA for fingerprinting the original cultivar has been demonstrated. DNA extraction was tested on four monovariety oils, plus four commercial extra virgin olive oils. The DNA in the extracted solution was of chloroplast and nuclear origin since we were able to amplify cloned cultivar RAPD and AFLP fragments homologous to nuclear DNA of other species. It has also been shown that DNA purified from oil can be used for AFLP analysis and that the profile of the DNA purified from a monovariety oil corresponds to the profile of the DNA purified from the leaves of the same cultivar.