Direct DNA amplification from virgin olive oil for traceability and authenticity

The olive tree is one of the most common fruit species cultivated for oil and table olives in Italy and, particularly, in the Mediterranean area. DNA fingerprinting methods include different markers; however, our work is based on the identification of olive oil cultivars by using simple sequence repeats analysis. As previously reported in the literature, this proposed method shows good capability to amplify, for example, DNA from wine and table grape varieties. In our paper, we suggest an easy methodology, which allows direct amplification of DNA and bypassing of the extraction of DNA using an engineered DNA polymerase, KAPA3G Plant DNA polymerase, improved to tolerate plant PCR inhibitors. This new procedure is more efficient, faster and cheaper than traditional methods of DNA extraction and amplification and leads to more accurate results. This innovative protocol, without the addition of chemical solutions, has provided good results and has permitted traceability of virgin olive oils.