Olive oil has been consumed in Italy for at least two thousand years. This is demonstrated by the analysis of the contents of a glass bottle found during the oldest phases of archaeological excavations in Herculaneum. The discovery by Campanian researchers is documented in the study published in the journal NPJ Science of Food. (1)
Alberto Angela's intuition
The ancient bottle of glass ‘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 of Naples. Where materials recovered during the oldest phases of archaeological excavations, started by Prince d’Elboeuf in 1738 and continued by Charles of Bourbon, are kept.
The idea to analyze its contents is due to Alberto Angela. The renowned paleontologist, science communicator, TV host, journalist, and writer – who followed in the footsteps of his famous father, Alberto Angela – had the opportunity to inspect the MANN storerooms. And observing a bottle still half full ‘of yellowish waxy organic matter, which solidified in the shape of a clarinet mouthpiece‘, he suggested analyzing it, hypothesizing that it might contain residues of wine or other food.
The discovery of olive oil
The analyses molecular, radiocarbon dating (a method that earned chemist Willard Libby the Nobel Prize in 1960) and further tests conducted by researchers ‘have for the first time allowed verifying the authenticity and characterizing the molecular identity of a sample of olive oil preserved inside a glass bottle buried by the eruption of Vesuvius in 79 AD‘.
By effect Due to the high temperatures to which the bottle was exposed during the eruption of Vesuvius – and the profound changes that have occurred in nearly two millennia of preservation under uncontrolled conditions – the analyzed substance shows traces of those deep chemical modifications that are typical of altered food fats.
Two thousand years of alterations
The fatty acid profile saturated and that of phytosterols then allowed certain identification of olive oil. Although very little has survived, among the molecules that characterize it:
– triglycerides, which represent 98% of the oil, have split into constituent fatty acids;
– unsaturated fatty acids have completely oxidized generating hydroxy acids. These, in turn, with slow kinetics, over about 2000 years, have reacted among themselves forming condensation products, estolides, never previously observed in conventional processes of natural alteration of olive oil.
Rancidification of the fatty substance has also produced a multitude of volatile substances, derived from the decomposition of oleic and linoleic acid.
The largest sample of ancient olive oil
In search has worked a team multidisciplinary team of researchers from the University of Naples Federico II, the CNR and the University of Campania Luigi Vanvitelli. Professor Raffaele Sacchi of the Department of Agriculture at the University of Naples Federico II briefly illustrates the outcome of the study he coordinated.
‘This is the oldest sample of olive oil we have received in large quantities, the oldest oil bottle in the world. The identification of the nature of the ‘archaeological oil bottle’ gives us irrefutable proof of the importance that olive oil had in the daily diet of the populations of the Mediterranean basin and in particular 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
Professional journalist since January 1995, she has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and magazines (NumeroUno, Il Salvagente). Author of journalistic investigations on food, she published the book 'Reading labels to know what we eat'.
