Long-chain ω-(o-alkylphenyl)alkanoic acids (APAAs) derived from the heating of unsaturated fatty acids have been widely used for the identification of aquatic products in archaeological ceramic vessels. To date, little attention has been paid to the diagnostic potential of shorter chain (< C 20 ) APAAs, despite their frequent occurrence. Here, a range of laboratory and field experiments and analyses of archaeological samples were undertaken to investigate whether APAAs could be used to further differentiate different commodities. The results provide new insights about the conditions for the formation of APAAs and enable the proposition of novel criteria to distinguish different natural products.

Chemical analysis of archaeological artefacts is used with increasing regularity to understand how wine was produced, traded, and consumed in the past and to shed light on its antiquity. Based both on an extensive review of the published literature and on new analyses, here we critically evaluate the diverse range of methodological approaches that have been used for wine identification. Overall, we conclude that currently none of the proposed chemical 'biomarkers' for wine provide unequivocal evidence. Nevertheless, valid interpretations may be offered if systematically supported by additional contextual data, such as archaeobotanical evidence. We found the extraction and detection method to be particularly crucial for successful identification. We urge the use of controls and quantification to rule out false positives. DNA sequencing offers potential for identifying wine and provides much higher taxonomic resolution, but work is needed to determine the limits of DNA survival on artefacts.

Sicily, during the 9th-12th century AD, thrived politically, economically, and culturally under Islamic political rule and the capital of Palermo stood as a cultural and political centre in the Mediterranean Islamic world. However, to what extent the lifeways of the people that experienced these regimes were impacted during this time is not well understood, particularly those from lesser studied rural contexts. This paper presents the first organic residue analysis of 134 cooking pots and other domestic containers dating to the 9th -12th century in order to gain new insights into the culinary practices during this significant period. Ceramics from three sites in the urban capital of Palermo and from the rural town of Casale San Pietro were analysed and compared. The multi-faceted organic residue analysis identified a range of commodities including animal products, vegetables, beeswax, pine and fruit products in the ceramics, with a complex mixing of resources observed in many cases, across all four sites and ceramic forms. Alongside the identification of commodities and how they were combined, new light has been shed on the patterning of resource use between these sites. The identification of dairy products in calcite wares from the rural site of Casale San Pietro and the absence of dairy in ceramics from the urban centre of Palermo presents interesting questions regarding the role of rural sites in food consumption and production in Islamic Sicily. This is the first time organic residue analysis of ceramics has been used to explore foodways in a medieval multi-faith society and offers new pathways to the understanding of pottery use and resources that were prepared, consumed and combined, reflecting cuisine in different socio-economic environments within the pluralistic population of medieval Sicily.

Although wine was unquestionably one of the most important commodities traded in the Mediterranean during the Roman Empire, less is known about wine commerce after its fall and whether the trade continued in regions under Islamic control. To investigate, here we undertook systematic analysis of grapevine products in archaeological ceramics, encompassing the chemical analysis of 109 transport amphorae from the fifth to the eleventh centuries, as well as numerous control samples. By quantifying tartaric acid in relation to malic acid, we were able to distinguish grapevines from other fruit-based products with a high degree of confidence. Using these quantitative criteria, we show beyond doubt that wine continued to be traded through Sicily during the Islamic period. Wine was supplied locally within Sicily but also exported from Palermo to ports under Christian control. Such direct evidence supports the notion that Sicilian merchants continued to capitalize on profitable Mediterranean trade networks during the Islamic period, including the trade in products prohibited by the Islamic hadiths, and that the relationship between wine and the rise of Islam was far from straightforward.

International audienceThe characterization of materials involved in painted works of art provides a better knowledge of artworks through the understanding of artistic and technological processes. In this study, some pieces selected from a large corpus of French Decorative Arts objects from 18 th century museum collections were analyzed. These materials are complex system made of a multilayered colored background, covered with varnish layers. Colored or gilded ornaments are applied, representing different characters, flowers or landscapes, then varnished again. The aim of this study was to improve the painting and varnishing techniques knowledge in the Decorative Arts field during the 18 th century. Vibrational spectroscopies, Raman, surface enhanced Raman spectroscopy (SERS) and infrared, were used to analyze some specific parts of these objects, especially organic materials such as lake pigments, binders and varnishes, and some of them were identified. For this purpose, a set of experimental setups and parameters were used according to the samples. The performed analyses were thus done using conventional FT-Raman at 1064 nm, SERS with a 458 nm excitation wavelength, infrared using a micro-ATR mode, and by defining for each technique and each analysed sample the best set of analytical parameters. The results obtained are all complementary and allowed us to completely identify and characterize multilayered paint systems as well as varnish compositions using specific data treatment methodology. This study is a description of the various possibilities that vibrational spectroscopies can provide when the right settings are employed, with a deeper look into the vibrational features using new data treatments

Post-firing treatments, produced by the interaction of an organic material with the hot surface of a ceramic, are frequently described in ethnographic literature, but have rarely been identified in archaeological ceramic assemblages. In order to address this question, this paper describes a methodology that combines macro-and microscopic observation and molecular analysis. The study of experimental ceramic vessels provided diagnostic tools to identify the type of substances, their liquid or solid state, and their mode of application and attested that the post-firing treatments do not completely waterproof the ceramics. The difficulty to observe macro-and microscopic evidence of post-firing treatments when pots are fired in reducing atmosphere suggests that these processes are probably underestimated in archaeological assemblages. Furthermore, the identification of molecular thermal transformation markers, such as ketones, calls into question their classical interpretation as markers for the cooking of fatty content. This pioneering work highlights the complexity of studying post-firing treatments, which leave small traces that are easily missed or misinterpreted. In order to address this issue, we propose a multi-analytical approach, which can serve as a basis for future studies to explore the full diversity of post-firing treatments mentioned in ethnoarchaeological literature.

The early phases of Neolithic expansion in the Central and Western Mediterranean are relatively poorly understood with regards to the diversity in the subsistence economy and the degree of interaction with indigenous hunter-gatherers. Recent analysis of pottery manufacturing techniques also points to a surprisingly diverse range of practices across the region. Here, we explore the use of pottery during the early phases of the Neolithic in the North-western Mediterranean, through analysis of organic residues absorbed in the pots of the Pendimoun rock-shelter (Impresso-Cardial complex) in South-eastern France. Using molecular and single-compounds stable carbon isotopes analyses, our study reveals that the majority of pots were used for processing wild or domesticated ruminant carcase fats, although lipids derived from cereals and wild non-ruminant fats, such as hares, cannot be excluded. In addition, a few of the earlier Impressa vessels showed the presence of beeswax and porcine fats. Correlations between the contents of the vessels and their volume were found, suggesting that vessels were manufactured for specific uses. Only one vessel from the Cardial phase showed evidence of dairy fats strengthening the notion that milk was not heavily or systematically exploited by the earliest Neolithic populations of the Mediterranean. Overall, however, our study calls for more detailed regional investigations to fully understand the transition to farming according to the local landscape and environmental context.

The excavation of the protohistoric site of Cuciurpula (South Corsica, France) revealed a significant amount of potsherds, often bearing visible surface crusts, sometimes very thick. This exceptional case in the Mediterranean region, suggesting a good preservation of organic substances, provided a unique opportunity to address questions related to pottery function and natural organic substances exploited in Corsica during the first half of the 1st millennium BC. The molecular analysis (GC and GC/MS) of organic residues from three houses of the site, preserved in both pottery walls and charred surface crusts, highlighted the wide diversity and the various roles of substances contained and processed in ceramic vessels: animal fats, plant oils and waxes, beeswax, and conifer resin. These molecular data, considered together with the shapes of the vessels and their location into the habitation units, revealed the diversity of pottery function (culinary and technical) and spatial organisation of domestic activities between houses or in a house (distinction between storage and cooking areas).