Shipwreck Yields World's Oldest Salad Dressing

June 20, 2008 -- Olive oil infused with fragrant herbs has been identified in an ancient Greek ceramic transport jar known as an amphora, along with another container of what could be the world's oldest retsina-type wine, according to a recent Journal of Archaeological Science paper.

It is the first time DNA has been extracted from shipwrecked artifacts -- the two large jars were recovered from a 2,400-year-old wrecked vessel off the Greek island of Chios. If the second jar indeed contained a retsina-like wine, which is preserved and flavored with a tree resin known as mastic, then the find would push back the known origins of mastic cultivation by 200 years.

"This (study) opens new possibilities for archaeologists -- now perhaps we can figure out what was carried in almost every 'empty' jar we find in land excavations or shipwrecks," researcher Brendan Foley of the Woods Hole Oceanographic Institution told Discovery News.

"Maybe we can even go back to the amphorae, jars and cooking pots previously excavated and now sitting in museum storerooms around the world and ask new questions of each artifact," he added.

The discoveries resulted from an international collaboration involving Foley, Swedish scientist Maria Hansson, and Greek archaeologists Dimitris Kourkoumelis and Theotokis Theodoulou of the Hellenic Ministry of Culture, overseen by Calliopi Preka-Alexandri and Vivi Vassilopoulou.

For the study, Hansson and Foley swabbed the jars with a chemical that allowed them to collect any genetic material inside. They then amplified and sequenced the DNA, comparing it to known DNA "signatures" from a database.

Since these signatures are unique for all plants and animals, they let researchers identify the source of the material in question.