The oldest bottle of olive oil found at Herculaneum

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Olive oil has been consumed in Italy for at least two thousand years. This is evidenced by an analysis of the contents of a glass bottle found during the earliest phases of archaeological excavations at Herculaneum. The Campania researchers’ discovery is documented in the study published in the journal NPJ Science of Food. (1)

Alberto Angela’s flair

The ancient glass bottle‘cylindrical, 25.5 cm high, with a single handle and short neck,’ similar to those depicted in frescoes found in Pompeii, is an artifact from the MANN collection-the National Archaeological Museum in Naples. Where materials recovered in the earliest stages of archaeological excavations, initiated by Prince d’Elboeuf in 1738 and continued by Charles of Bourbon, are kept.

The idea of analyzing its contents is due to Alberto Angela. The well-known paleontologist, science popularizer, TV host, journalist and writer – who followed in the footsteps of his celebrated father, Alberto Angela – had the opportunity to make an inspection of the MANN’s storerooms. And observing a bottle still half full‘of yellowish waxy organic matter, solidifying in the shape of a clarinet spout,’ he suggested analyzing it. Assuming that it might contain residues of wine or other food.

The discovery of olive oil

The analyses molecular, carbon-14 dating (a method that earned chemist Willard Libby the Nobel Prize in 1960), and the additional tests conducted by researchers ‘have made it possible for the first time to verify the authenticity and characterize the molecular identity of a sample of olive oil preserved inside a glass bottle buried by the eruption of Vesuvius in 79 AD‘.

For effect of the high temperatures to which the bottle was exposed during the eruption of Vesuvius-and the profound changes that have occurred over the nearly two millennia of storage under uncontrolled conditions-the substance analyzed shows evidence of the profound chemical changes that are typical of altered food fats.

Two thousand years of alterations

The profile of saturated fatty acids and that of phytosterols then made it possible to identify olive oil with certainty. Although very little has survived, among the molecules that characterize it:

– triglycerides, which account for 98 percent of the oil, have broken down into the constituent fatty acids;

– unsaturated fatty acids were completely oxidized, generating hydroxy acids. The latter, in turn, with slow kinetics, over the course of about 2,000 years, reacted with each other to form condensation products, the estolids, never previously observed in conventional processes of natural alteration of olive oil.

The rancidity of the fatty substance also produced a multitude of volatile substances, derived from the decomposition ofoleic and linoleicacid.

The largest sample of ancient olive oil

A multidisciplinary team of researchers from the University of Naples Federico II, the CNR and the University of Campania Luigi Vanvitelli worked on the research. Professor Raffaele Sacchi of the Department of Agriculture at the University of Naples Federico II, so briefly explains the outcome of the study he coordinated.

‘This is the oldest sample of olive oil to have come down to us in large quantities, the oldest bottle of oil in the world. The identification of the nature of the ‘archaeological oil bottle’ gives us irrefutable evidence of the importance that olive oil had in the daily diet of the people of the Mediterranean basin and particularly of the ancient Romans in Campania Felix’.

Notes

1) Sacchi, R., Cutignano, A., Picariello, G. et al. Olive oil from the 79 A.D. Vesuvius eruption stored at the Naples National Archaeological Museum (Italy). npj Sci Food 4, 19 (2020). doi: https://doi.org/10.1038/s41538-020-00077-w. V. https://www.nature.com/articles/s41538-020-00077-w

Marta Strinati

Professional journalist since January 1995, he has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and periodicals (NumeroUno, Il Salvagente). She is the author of journalistic surveys on food, she has published the book "Reading labels to know what we eat".