Analytical strategies for discriminating archeological fatty substances from animal origin

Study of oxidation products in aged olive oils by GC and HPLC techniques coupled to mass spectrometry to discriminate olive oil lipid substances in archaeological artifacts from ancient Taormina (Italy)

The identification of archaeological biomarkers is one of the main objectives of analytical chemistry in the archaeological field. However, no information is currently available on biomarkers able to unambiguously indicate the presence of olive oil, a cornerstone of Mediterranean ancient societies lifestyle, in an organic residue. This study aims to bridge this gap by a thorough characterization of the degradation products of extra-virgin olive oils (EVOOs) resulting from in-lab thermal oxidative treatments, with the primary goal of revealing potential archaeological biomarkers for olive oil. Thirty-three EVOOs sourced from eleven different monocultivars across five Italian regions (Sicily, Apulia, Lazio, Tuscany, and Liguria) and Spain, were analyzed before and after thermal oxidation. In addition, an identical thermal treatment was employed on pure triglyceride standards (triolein, trilinolein, and tristearin), due to the high concentration of their fatty acids in EVOO discerning their degradation patterns. A combination of analytical strategies was employed, including HPLC-MS and HPLC-ELSD for the complete evaluation of the intact lipids (triglycerides, diglycerides, and their oxidative species) in olive oils before and after oxidation, and HS-SPME-GC-MS and GC-FID for the characterization of secondary oxidation products formed by the thermal treatment. In addition, to elucidate the fatty acid distribution in the oxidized EVOOs by GC-MS and GC-FID techniques a derivatization step was performed to convert lipid compounds into trimethylsilyl (TMS) derivatives. A chemometric approach was used to thoroughly interpret the data obtained from intact and oxidized samples. This comprehensive investigation sheds light on the chemical transformations of EVOOs under thermal oxidative conditions and indicates mono-carboxylic acids such as pentanoic, hexanoic, heptanoic, octanoic, nonanoic, and decanoic acids as potential archaeological biomarkers for the presence of lipid substances coming from olive oil in archaeological organic residues. Finally, lipid contents from twenty-four real archaeological samples, grouped in amphorae (10), unguentaria (5), and lamps (9), excavated from the Roman domus of Villa San Pancrazio in Taormina (Italy), were determined. The analytical results obtained from amphorae samples revealed the presence of the selected olive oil-specific archaeological biomarkers, an information extremely interesting considering that this type of amphorae have so far been solely associated with the storage of wine.

Pottery spilled the beans: Patterns in the processing and consumption of dietary lipids in Central Germany from the Early Neolithic to the Bronze Age

The need to better understand economic change and the social uses of long-ago established pottery types to prepare and consume food has led to the study of 124 distinct ceramic vessels from 17 settlement and funerary sites in Central Germany (present day Saxony-Anhalt). These, dated from the Early Neolithic (from 5450 cal. BCE onwards) to the Late Bronze Age (1300-750 cal. BCE; youngest sample ca. 1000 BCE), include vessels from the Linear Pottery (LBK), Schiepzig/Schöningen groups (SCHIP), Baalberge (BAC), Corded Ware (CWC), Bell Beaker (BBC), and Únětice (UC) archaeological cultures. Organic residue analyses performed on this assemblage determined the presence of vessel contents surviving as lipid residues in 109 cases. These were studied in relation to the changing use of settlement and funerary pottery types and, in the case of burials, to the funerary contexts in which the vessels had been placed. The obtained results confirmed a marked increase in the consumption of dairy products linked to innovations in pottery types (e.g., small cups) during the Funnel Beaker related Baalberge Culture of the 4th millennium BCE. Although the intensive use of dairy products may have continued into the 3rd millennium BCE, especially amongst Bell Beaker populations, Corded Ware vessels found in funerary contexts suggest an increase in the importance of non-ruminant products, which may be linked to the production of specific vessel shapes and decoration. In the Early Bronze Age circum-Harz Únětice group (ca. 2200-1550 BCE), which saw the emergence of a highly hierarchical society, a greater variety of animal and plant derived products was detected in a much more standardised but, surprisingly, more multifunctional pottery assemblage. This long-term study of lipid residues from a concise region in Central Europe thus reveals the complex relationships that prehistoric populations established between food resources and the main means to prepare, store, and consume them.

From bowls to pots: The dairying revolution in Northwest Turkey, a view from Barcın Höyük, 6600 to 6000 BCE

Research has identified Northwest Turkey as a key region for the development of dairying in the seventh millennium BCE, yet little is known about how this practice began or evolved there. This research studies Barcın Höyük, a site located in Bursa's Yenişehir Valley, which ranges chronologically from 6600 BCE, when the first evidence of settled life appears in the Marmara Region, to 6000 BCE, when Neolithic habitation at the site ceases. Using pottery sherds diagnostic by vessel category and type, this paper aims at identifying which ones may have been primarily used to store, process, or consume dairy products. Organic residue analysis of selected samples helped address the process of adoption and intensification of milk processing in this region over time. The lipid residue data discussed in this paper derive from 143 isotopic results subsampled from 173 organic residues obtained from 805 Neolithic potsherds and suggest that bowls and four-lugged pots may have been preferred containers for processing milk. The discovery of abundant milk residues even among the earliest ceramics indicates that the pioneer farmers arrived in the region already with the knowhow of dairying and milk processing. In fact, these skills and the reliance on secondary products may have given them one of the necessary tools to successfully venture into the unfarmed lands of Northwest Anatolia in the first place.

Fatty Acids and Starch Identification within Minute Archaeological Fragments: Qualitative Investigation for Assessing Feasibility

Within the realm of archaeology, the analysis of biomolecules assumes significant importance in elucidating historical dietary patterns and their implications for contemporary contexts. To achieve this, knowledge and tools of both chemistry and archaeology are essential to yield objective outcomes and conduct analyses of archaeological materials for the detection of biomolecules. Usually, only minuscule remnants of ceramic fragments are retrieved from excavations, which limits the feasibility of comprehensive laboratory analysis. This study aimed to establish a protocol for analyzing fatty acids and starch from archaeological food utensils with minimal sample quantities. Various experiments were conducted to replicate preparations that might have occurred in archaeological vessels, aiming to establish the optimal protocol. The analyses were performed using clay griddles, subjecting vegetable oil to varying temperatures for fatty acid assessment. For starch analysis, a series of experiments encompassed diverse forms of potato preparations (pulp, chuño, tortilla, carbonization, and freeze-drying) and maize (flour, tortilla, and carbonization). The verification of the experiments was confirmed by conducting identical analyses, as developed in the current study, on authentic archaeological fragments. The principal outcomes of this investigation include the successful extraction of both types of biomolecules using only 0.25 g of the sample, obtained through direct scraping from the vessel. Soxhlet extraction was identified as the most efficient strategy to recover fatty acids. Additionally, a comprehensive protocol for the identification of starch extraction was developed. This study has, for the first time, elucidated two detailed methodologies for the extraction of fatty acids and starch in scenarios in which researchers can obtain limited quantities of archaeological food utensil fragments.

Assessing the usefulness of Raman spectroscopy and lipid analysis of decomposed human bones in forensic genetics and molecular taphonomy

Bones are among the structures most likely to be recovered after death. However, the low quantity of preserved DNA and complex processing from sample to DNA profile make forensic DNA analysis of bones a challenging task. Raman spectroscopy and gas chromatography-mass spectrometry (GC/MS), have the potential to be useful as screening tools for DNA analysis and in decomposition studies. The objective of this research was to assess the usefulness of such molecular investigations. Femur samples collected from 50 decomposing human bodies were subjected to Raman spectroscopy and GC/MS. Assessment of nuclear DNA quantity and short tandem repeat (STR) genotyping efficiency were also performed. Raman parameters (crystallinity, carbonate-to-phosphate ratio, mineral-to-matrix ratio) and detected lipids were recorded. Background fluorescence proved problematic for Raman analysis of forensic bones. Regardless, it was not associated with less preserved DNA or less detected STR alleles. Fatty acids, hydrocarbons, and five types of fatty acid methyl esters (FAMEs) were detected. The main phosphate peak position in Raman spectra was significantly correlated with preserved DNA (p = 0.03713), while significantly more STR alleles were detected in bones containing methyl hexadecenoate (p = 0.04236). Detection of FAMEs in the bone matrix suggests a reaction between methanol produced by bacteria and free fatty acids, which are not associated with the level of preservation of endogenous DNA. The techniques assessed have shown to be useful in molecular taphonomy studies and forensic genetics.

Interdisciplinary evidence for early domestic horse exploitation in southern Patagonia

The introduction of domestic horses transformed Indigenous societies across the grasslands of Argentina, leading to the emergence of specialized horse cultures across the Southern Cone. However, the dynamics of this introduction are poorly chronicled by historic records. Here, we apply archaeozoological and biomolecular techniques to horse remains from the site of Chorrillo Grande 1 in southern Argentina. Osteological and taphonomic analyses suggest that horses were pastorally managed and used for food by Aónikenk/Tehuelche hunter-gatherers before the onset of permanent European settlement, as early as the mid-17th century. DNA-based sex identifications suggest consumption of both male and female horses, while ceramic residue also shows use of guanaco products. Sequential isotope analyses on horse dentition reveal an origin in southern Patagonia and movement of these animals between the Río Coig and Río Gallegos basins. These results reinforce emerging evidence for rapid Indigenous-mediated dispersal of horses in the Americas and demonstrate that horses catalyzed rapid economic and social transformations.

Investigating livestock management in the early Neolithic archaeological site of Cabecicos Negros (Almería, Spain) from the organic residue analysis in pottery

This paper seeks to reconstruct the management of food resources in the early Neolithic site of Cabecicos Negros in southeastern Spain. For this purpose, we have studied 29 potsherds from Cabecicos Negros (Andalusia, Spain). Applying the methods of gas chromatography and mass spectrometry we were able to recompose the daily use of the sherds related to the consumption and storage of food products. Among the results obtained in this work, we were able to show new evidence of the exploitation of dairy products in the south of the Iberian Peninsula, as well as provide information on the exploitation and management of the early domestic animals herds. To improve the archaeological results obtained, isotopic results were compared with a modern reference of 53 fat samples from the adipose tissue of domestic pigs and wild boars.

Biomolecular analyses enable new insights into ancient Egyptian embalming

The ability of the ancient Egyptians to preserve the human body through embalming has not only fascinated people since antiquity, but also has always raised the question of how this outstanding chemical and ritual process was practically achieved. Here we integrate archaeological, philological and organic residue analyses, shedding new light on the practice and economy of embalming in ancient Egypt. We analysed the organic contents of 31 ceramic vessels recovered from a 26th Dynasty embalming workshop at Saqqara^1,2. These vessels were labelled according to their content and/or use, enabling us to correlate organic substances with their Egyptian names and specific embalming practices. We identified specific mixtures of fragrant or antiseptic oils, tars and resins that were used to embalm the head and treat the wrappings using gas chromatography-mass spectrometry analyses. Our study of the Saqqara workshop extends interpretations from a micro-level analysis highlighting the socio-economic status of a tomb owner^3-7 to macro-level interpretations of the society. The identification of non-local organic substances enables the reconstruction of trade networks that provided ancient Egyptian embalmers with the substances required for mummification. This extensive demand for foreign products promoted trade both within the Mediterranean^8-10 (for example, Pistacia and conifer by-products) and with tropical forest regions (for example, dammar and elemi). Additionally, we show that at Saqqara, antiu and sefet-well known from ancient texts and usually translated as 'myrrh' or 'incense'^11-13 and 'a sacred oil'^13,14-refer to a coniferous oils-or-tars-based mixture and an unguent with plant additives, respectively.

Unveiling the Use of Wide Horizontal Rim Vessels (Bronze Age Northwest Iberian Peninsula)

This paper addresses a “wide horizontal rim vessel” belonging to the collection of Fundação Sousa d’Oliveira (Azores). Although its provenance and the circumstances of its discovery are currently unknown, the authors contend that this vessel should be attributed to the Iberian Northwest and, more specifically, to the Portuguese territory, in line with the highly homogenous distribution of this type of pottery. A morphological and stylistic study has been carried out establishing its singularity with regards to the decorative composition of the rim, which is without parallel amongst dozens of vessels of the same “family”. During the study of this piece, it has been possible to observe traces of soot and organic residues deposited both on its interior and exterior surfaces, which is recurrent in these vessels. The nature of these substances has never been determined in previous studies. In this article, we present and discuss the results obtained from the chromatographic analyses of the organic residue traces found on the vessel.

Lipids in Archaeological Pottery: A Review on Their Sampling and Extraction Techniques

Several studies have been performed so far for the effective recovery, detection and quantification of specific compounds and their degradation products in archaeological materials. According to the literature, lipid molecules are the most durable and widespread biomarkers in ancient pottery. Artificial ageing studies to simulate lipid alterations over time have been reported. In this review, specific lipid archaeological biomarkers and well-established sampling and extraction methodologies are discussed. Although suitable analytical techniques have unraveled archaeological questions, some issues remain open such as the need to introduce innovative and miniaturized protocols to avoid extractions with organic solvents, which are often laborious and non-environmentally friendly.

Recipes of Ancient Egyptian kohls more diverse than previously thought

Kohl, a dark eye cosmetic, is a well-known part of Ancient Egyptian culture. Modern chemical analyses of kohls have largely found lead-based inorganic constituents, whereas earlier studies argued for a much broader range of constituents. Furthermore, organic materials in kohls remain severely understudied. This raises questions regarding the true diversity of materials and recipes used to produce kohls. We analysed the contents of 11 kohl containers from the Petrie Museum collection in London. The objects selected cover a broad range of times and locations in Egypt. Our multi-analytical approach allowed us to characterise both inorganic and organic components. Our data show that inorganic ingredients in kohl recipes are not only lead-based but also manganese- and silicon-based. Our analyses also revealed that organic ingredients derived from both plant and animal sources were commonly used in kohl recipes and sometimes even represent the main constituent. All these findings point towards more varied recipes than initially thought and significantly shift our understanding of Ancient Egyptian kohls.

Fatty Acids and Their Metal Salts: A Review of Their Infrared Spectra in Light of Their Presence in Cultural Heritage

In a cultural heritage context, fatty acids are usually found as breakdown products of lipid-containing organic remains in archaeological findings, binders in aged oil paintings, and additives in modern art-related materials. They may further interact with the ionic environment transforming into metal soaps, a process that has been recognized as a threat in aged paintings but has received less attention in archaeological objects. The investigation of the above related categories of materials with infrared spectroscopy can provide an overall picture of the organic components' identity and demonstrate their condition and prehistory. The capability of investigating and distinguishing fatty acids and their metal soaps through their rich infrared features, such as the acidic carbonyl, the carboxylate shifts, the variable splits of alkyl chain stretching, bending, twisting, wagging, and rocking vibrations, as well as the hydroxyl peak envelopes and acid dimer bands, allows for their direct detailed characterization. This paper reviews the infrared spectra of selected saturated fatty monoacids and diacids, and their corresponding sodium, calcium, and zinc salts and, supported by newly recorded data, highlights the significance of their spectroscopic features.

Liquid chromatography and mass spectrometry for the analysis of acylglycerols in art and archeology

Lipid characterization in art and archeology, together with the study of lipid degradation processes, is an important research area in heritage science. Lipid-based materials have been used as food since ancient times, but also employed as illuminants and as ingredients in cosmetic, ritual, and pharmaceutical preparations. Both animal and plant lipids have also been processed to produce materials used in art and crafts, such as paint binders, varnishes, waterproofing agents, and coatings. Identifying the origin of the lipid materials is challenging when they are found in association with artistic historical objects. This is due to the inherent complex composition of lipids, their widespread occurrence, and the chemical alterations induced by ageing. The most common approach for lipid characterization in heritage objects entails profiling fatty acids by gas chromatography/mass spectrometry after saponification or transesterification. New developments in high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS) for the characterization of acylglycerols, together with more efficient sample treatments, have fostered the introduction of liquid chromatography for characterizing the lipid profile in heritage objects. This review reports the latest developments and applications of HPLC-MS for the characterization of lipid materials in the field of heritage science. We describe the various approaches for sample pretreatment and highlight the advantages and limitations of HPLC-MS in the analysis of paint and archeological samples. © 2020 John Wiley & Sons Ltd.

Bile acids and oxo-metabolites as markers of human faecal input in the ancient Pompeii ruins

Small organic molecules, lipids, proteins, and DNA fragments can remain stable over centuries. Powerful and sensitive chemical analysis can therefore be used to characterize ancient remains for classical archaeological studies. This bio-ecological dimension of archaeology can contribute knowledge about several aspects of ancient life, including social organization, daily habits, nutrition, and food storage. Faecal remains (i.e. coprolites) are particularly interesting in this regard, with scientists seeking to identify new faecal markers. Here, we report the analysis of faecal samples from modern-day humans and faecal samples from a discharge pit on the site of the ruins of ancient Pompeii. We propose that bile acids and their gut microbiota oxo-metabolites are the most specific steroid markers for detecting faecal inputs. This is due to their extreme chemical stability and their exclusive occurrence in vertebrate faeces, compared to other ubiquitous sterols and steroids.

Lipid residues in pottery from the Indus Civilisation in northwest India

This paper presents novel insights into the archaeology of food in ancient South Asia by using lipid residue analysis to investigate what kinds of foodstuffs were used in ceramic vessels by populations of the Indus Civilisation in northwest India. It examines how vessels were used in urban and rural Indus settlements during the Mature Harappan period (c.2600/2500-1900 BC), the relationship between vessels and the products within them, and identifies whether changes in vessel use occurred from the Mature Harappan to Late Harappan periods, particularly during climatic instability after 4.2 ka BP (c.2100 BC). Despite low lipid concentrations, which highlight challenges with conducting residue analysis in arid, seasonally-wet and alkaline environments, 71% of the vessels yielded appreciable quantities of lipid. Lipid profiles revealed the use of animal fats in vessels, and contradictory to faunal evidence, a dominance of non-ruminant fats, with limited evidence of dairy processing. The absence of local modern reference fats makes this dataset challenging to interpret, and it is possible that plant products or mixtures of plant and animal products have led to ambiguous fatty acid-specific isotopic values. At the same time, it appears that urban and rural populations processed similar types of products in vessels, with limited evidence for change in vessel use from the urban to the post-urban period. This study is a systematic investigation into pot lipid residues from multiple sites, demonstrating the potential of the method for examining ancient Indus foodways and the need for the development of further research in ancient organic residues in South Asia.

Olive oil from the 79 A.D. Vesuvius eruption stored at the Naples National Archaeological Museum (Italy)

Using a range of chromatographic, spectroscopic, and mass spectrometric analytical techniques, we characterized one of the "edible items" found at the Vesuvius archeological sites and guarded at the National Archaeological Museum of Naples (MANN) in Naples, Italy. We authenticated the specimen contained in a glass bottle (Mann-S1 sample) as originally olive oil and mapped the deep evolution throughout its 2000 years of storage. Triacylglycerols were completely hydrolyzed, while the resulting (hydroxy) fatty acids had partly condensed into rarely found estolides. A complex pattern of volatile compounds arose mainly from breakdown of oleic acid. With excellent approximation, radiocarbon dating placed the find at the time of the Plinian Mount Vesuvius eruption in 79 A.D., indicating that Mann-S1 is probably the oldest residue of olive oil in the world found in bulk amount (nearly 0.7 L).

Digging deeper - A new data mining workflow for improved processing and interpretation of high resolution GC-Q-TOF MS data in archaeological research

Gas chromatography-mass spectrometry profiling is the most established method for the analysis of organic residues, particularly lipids, from archaeological contexts. This technique allows the decryption of hidden chemical information associated with archaeological artefacts, such as ceramic pottery fragments. The molecular and isotopic compositions of such residues can be used to reconstruct past resource use, and hence address major questions relating to patterns of subsistence, diet and ritual practices in the past. A targeted data analysis approach, based on previous findings reported in the literature is common but greatly depends on the investigator’s prior knowledge of specific compound classes and their mass spectrometric behaviour, and poses the risk of missing unknown, potentially diagnostic compounds. Organic residues from post-prehistoric archaeological samples often lead to highly complex chromatograms, which makes manual chromatogram inspection very tedious and time consuming, especially for large datasets. This poses a significant limitation regarding the scale and interpretative scopes of such projects. Therefore, we have developed a non-targeted data mining workflow to extract a higher number of known and unknown compounds from the raw data to reduce investigator’s bias and to vastly accelerate overall analysis time. The workflow covers all steps from raw data handling, feature selection, and compound identification up to statistical interpretation.

Selected elements and fatty acid composition in human milk as indicators of seafood dietary habits

The maternal diet and living environment can affect levels of chemical elements and fatty acid (FA) composition and their stable isotopes (δ¹³C_FA) in human milk. Information obtained from questionnaires is frequently imprecise, thus limiting proper associations between external and internal exposures as well as health effects. In this study, we focused on seafood as a source of potentially toxic and essential elements and nutritional FAs. Concentrations of selected elements in human milk (As, Cd, Cu, Mn, Pb, Se and Zn) were determined using inductively coupled plasma mass spectrometry (ICP-MS) and Hg using cold vapour atomic-absorption spectrometry (CV-AAS). The identification and quantification of FAs in maternal milk were performed by an in-situ trans-esterification method (FAMEs), and the characterization of FAMEs was performed by gas chromatography with a flame ionisation detector (GC-FID). δ¹³C_FA was determined by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). Seventy-four lactating Slovenian women from the coastal area of Koper (KP), with more frequent consumption of seafood, and the inland area of Pomurje (MS), with less frequent seafood consumption, were included in this study. Along with basic statistical analyses, data mining approaches (classification and clustering) were applied to investigate whether FA composition and δ¹³C_FA could improve the information regarding dietary sources of potentially toxic elements. As and Hg levels in milk were found to be statistically higher in populations from KP than in those from MS, and 71% of individual FAs and 30% of individual δ¹³C_FA values in milk differed statistically between the studied areas. In 19 cases, the levels of FAs in milk were higher in KP than in MS; these FAs include C20:5ω3 and C22:6ω3/C24:1ω9, which are typically contained in fish. In 16 cases, the mean percentage of FAs was higher in MS than in KP; these FAs include the PUFAs C18:2ω6, C18:3ω3, and C20:4ω6 which are important for human and infant growth. The difference in δ¹³C levels of C10:0, C12:0, C14:0, C16:1, C16:0, C18:1ω9c, C22:6ω3, and δ¹³C 18:0-16:0 in the study groups was statistically significant. In all seven cases where δ¹³C of FA significantly differed between KP and MS, δ¹³C was higher in KP, indicating a higher proportion of a marine-based diet. The data mining approaches confirmed that the percentage of selected FAs (iC17:0, C4:0, C18:2ω6t, aC17:0, CLA, and C22:4ω6) and δ¹³C_FA of C18:1ω9c in human milk could be used to distinguish between high and low frequency of fresh seafood consumption.

The dynamics of Early Celtic consumption practices: A case study of the pottery from the Heuneburg

The Early Celtic site of the Heuneburg (Baden-Wuerttemberg, Germany) has long been understood as a hallmark of early urbanization in Central Europe. The rich collection of Mediterranean imports recovered from the settlement, the elite burials in its surroundings and the Mediterranean-inspired mudbrick fortification wall further point to the importance of intercultural connections with the Mediterranean as a crucial factor in the transformation of Early Iron Age societies. We describe a new facet of this process by studying the transformation of consumption practices, especially drinking habits, brought about by intercultural encounters from the late 7^th to the 5^th century BC through the analysis of organic remains in 133 ceramic vessels found at the Heuneburg using Organic Residue Analysis (ORA). During the Ha D1 phase, fermented beverages, including Mediterranean grape wine, were identified in and appear to have been consumed from local handmade ceramics. The latter were recovered from different status-related contexts within the Heuneburg, suggesting an early and well-established trade/exchange system of this Mediterranean product. This contrasts with the results obtained for the drinking and serving vessels from the Ha D3 phase that were studied. The consumption of fermented beverages (wine and especially bacteriofermented products) appears to have been concentrated on the plateau. The ORA analyses presented here seem to indicate that during this time, grape wine was consumed primarily from imported vessels, and more rarely from local prestigious fine wheel-made vessels. In addition to imported wine, we demonstrate the consumption of a wide variety of foodstuffs, such as animal fats (especially dairy products), millet, plant oils and waxy plants, fruit and beehive products as well as one or several other fermented beverage(s) that were probably locally produced. Through this diachronic study of vessel function from different intra-site contexts, we inform on changing and status-related practices of food processing and consumption.

New insights into Early Celtic consumption practices: Organic residue analyses of local and imported pottery from Vix-Mont Lassois

The rich Mediterranean imports found in Early Celtic princely sites (7^th-5^th cent. BC) in Southwestern Germany, Switzerland and Eastern France have long been the focus of archaeological and public interest. Consumption practices, particularly in the context of feasting, played a major role in Early Celtic life and imported ceramic vessels have consequently been interpreted as an attempt by the elite to imitate Mediterranean wine feasting. Here we present the first scientific study carried out to elucidate the use of Mediterranean imports in Early Celtic Central Europe and their local ceramic counterparts through organic residue analyses of 99 vessels from Vix-Mont Lassois, a key Early Celtic site. In the Mediterranean imports we identified imported plant oils and grape wine, and evidence points towards appropriation of these foreign vessels. Both Greek and local wares served for drinking grape wine and other plant-based fermented beverage(s). A wide variety of animal and plant by-products (e.g. fats, oils, waxes, resin) were also identified. Using an integrative approach, we show the importance of beehive products, millet and bacteriohopanoid beverage(s) in Early Celtic drinking practices. We highlight activities related to biomaterial transformation and show intra-site and status-related differences in consumption practices and/or beverage processing.

Insights into the timing, intensity and natural setting of Neanderthal occupation from the geoarchaeological study of combustion structures: A micromorphological and biomarker investigation of El Salt, unit Xb, Alcoy, Spain

Middle Paleolithic lithic and faunal assemblages throughout Eurasia reflect short-term Neanderthal occupations, which suggest high group mobility. However, the timing of these short-term occupations, a key factor to assess group mobility and territorial range, remains unresolved. Anthropogenic combustion structures are prominent in the Middle Paleolithic record and conceal information on the timing and intensity and natural setting of their associated human occupations. This paper examines a concentration of eleven combustion structures from unit Xb of El Salt, a Middle Paleolithic site in Spain through a geoarchaeological approach, in search of temporal, human impact and paleoenvironmental indicators to assess the timing, intensity and natural setting of the associated human occupations. The study was conducted using micromorphology, lipid biomarker analysis and compound specific isotope analysis. Results show in situ hearths built on different diachronic topsoils rich in herbivore excrements and angiosperm plant residues with rare anthropogenic remains. These data are suggestive of low impact, short-term human occupations separated by relatively long periods of time, with possible indicators of seasonality. Results also show an absence of conifer biomarkers in the mentioned topsoils and presence of conifer charcoal among the fuel residues (ash), indicating that fire wood was brought to the site from elsewhere. A microscopic and molecular approach in the study of combustion structures allows us to narrow down the timescale of archaeological analysis and contributes valuable information towards an understanding of Neanderthal group mobility and settlement patterns.

Analytical Interpretation of Organic Residues From Ceramics As a Source of Knowledge About Our Ancestors

Food ingredients which were prepared or stored in the archeological ceramics are the most frequently used in the study of ceramic vessels with the use of various types of gas chromatographic methods. These include lipids which contain fatty acids and compounds characteristic of various types of food known as archeological biomarkers. The paper shows how the lipid profile analysis and its interpretation can be helpful to explain the source of organic substances preserved in archeological ceramic vessels. The presence of characteristic sterols discriminates between plant (phytosterols) and animal (zoosterols) residues. Based on the calculated proportions of selected fatty acids, the animal residues can be precisely identified as originating from fish, ruminants or monogastric animals. Many authors have created their own methods of interpretation and conclusion, which makes it possible to sort out all the information gathered about the historical purpose of clay vessels. Due to the fact that the presented research still raises some doubts and questions, it is important for the interpretation of the results of chemical analysis to be considered in the archeological context. The ability to properly explain the meaning of the results of analyses is crucial for a better understanding of the life and customs of our ancestors.

Ancient proteins from ceramic vessels at Çatalhöyük West reveal the hidden cuisine of early farmers

The analysis of lipids (fats, oils and waxes) absorbed within archaeological pottery has revolutionized the study of past diets and culinary practices. However, this technique can lack taxonomic and tissue specificity and is often unable to disentangle signatures resulting from the mixing of different food products. Here, we extract ancient proteins from ceramic vessels from the West Mound of the key early farming site of Çatalhöyük in Anatolia, revealing that this community processed mixes of cereals, pulses, dairy and meat products, and that particular vessels may have been reserved for specialized foods (e.g., cow milk and milk whey). Moreover, we demonstrate that dietary proteins can persist on archaeological artefacts for at least 8000 years, and that this approach can reveal past culinary practices with more taxonomic and tissue-specific clarity than has been possible with previous biomolecular techniques.

Characteristics and compound-specific carbon isotope compositions of sedimentary lipids in high arsenic aquifers in the Hetao basin, Inner Mongolia

Organic matter, as an electron donor, plays a vital role in As mobilization mediated by microorganisms during reductive dissolution of Fe/Mn oxides in shallow aquifers. However, the specific types and sources of organic matter involved in biogeochemical processes accelerating As mobilization are still controversial. Both sediment and groundwater samples were collected at different depths from aquifers of the Hetao Basin, a typical inland basin hosting high As groundwater. Sedimentary lipids and their compound-specific carbon isotope ratios were analyzed to evaluate characteristics and sources of organic matter. Results show that sedimentary As were well correlated with Fe and Mn oxides, suggesting that As exist as Fe/Mn oxide bound forms. Groundwater As far exceeded the drinking water guide value of 10 μg/L. Moreover, As concentrations in shallow groundwater were relatively higher. Lipids in clay were mainly originated from terrestrial higher plants, while that in fine sand samples were derived from terrestrial higher plants, microorganism and petroleum. Shallow fine sand samples were also characterized by evident in-situ biodegradation. Compound-specific carbon isotope compositions of sedimentary lipids showed that short-chain n-alkanes and n-alkanoic acids had more positive δ¹³C values compared to long-chain compounds, especially in shallow fine sand samples. δ¹³C_TOC were also low in shallow fine sand samples. These results jointly indicate that these lipids in shallow fine sand samples acted as carbon source for indigenous microorganism and the short-chain components were particularly more vulnerable to biodegradation, which may contribute to high As concentrations in shallow groundwater. The new findings provide the first evidence that short chain length n-alkyl compounds afforded a source of potential electron donors for microbially mediated As mobilization process in the shallow aquifers.

Fatty acid specific δ13C values reveal earliest Mediterranean cheese production 7,200 years ago

The earliest evidence for cheese production in the Mediterranean is revealed by stable carbon isotope analyses of individual fatty acids in pottery residues from the Dalmatian coast of Croatia. Lipid residue data indicate the presence of milk in the earliest pottery, Impressed Ware, by 5700 cal. BCE (7700 BP). In contrast, by 5200 cal BCE (7200 BP), milk was common in refined Figulina pottery, meat was mostly associated with Danilo ware, cheese occurred in Rhyta, and sieves contained fermented dairy, representing strong links between specific function and stylistically distinctive pottery vessels. Genetic data indicate the prevalence of lactose intolerance among early farming populations. However, young children are lactase persistent until after weaning and could consume milk as a relatively pathogen-free and nutrient rich food source, enhancing their chances of survival into adulthood. Fermentation of milk into yogurt and cheese decreases lactose content. The evidence for fermented dairy products by 5200 cal BCE indicates a larger proportion of the population was able to consume dairy products and benefit from their significant nutritional advantages. We suggest that milk and cheese production among Europe’s early farmers reduced infant mortality and helped stimulate demographic shifts that propelled farming communities to expand to northern latitudes.

The Studies of Archaeological Pottery with the Use of Selected Analytical Techniques

Modern analytical methods play an important role in archaeological objects, including ceramics. This review focuses on the use of analytical methods such as: gas chromatography coupled mass spectrometry, Fourier transform infrared spectroscopy, time-of-flight secondary ion mass spectrometry (ToF-SIMS), powder X-ray diffraction with thermal analysis to study the chemical and mineralogical composition of archaeological samples and organic residues preserved inside. In this paper, special attention was paid to the ToF-SIMS method, which allows the determination of characteristic ions on the surface of ceramic samples.

MALDI-FT-ICR-MS for archaeological lipid residue analysis

Soft-ionization methods are currently at the forefront of developing novel methods for analysing degraded archaeological organic residues. Here, we present little-used soft ionization method of matrix assisted laser desorption/ionization-Fourier transform-ion cyclotron resonance-mass spectrometry (MALDI-FT-ICR-MS) for the identification of archaeological lipid residues. It is a high-resolution and sensitive method with low limits of detection capable of identifying lipid compounds in small concentrations, thus providing a highly potential new technique for the analysis of degraded lipid components. A thorough methodology development for analysing cooked and degraded food remains from ceramic vessels was carried out, and the most efficient sample preparation protocol is described. The identified components, also controlled by independent parallel analysis by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS), demonstrate its capability of identifying very different food residues including dairy, adipose fats as well as lipids of aquatic origin. The results obtained from experimentally cooked and original archaeological samples prove the suitability of MALDI-FT-ICR-MS for analysing archaeological organic residues. Sample preparation protocol and identification of compounds provide future reference for analysing various aged and degraded lipid residues in different organic and mineral matrices.

Open sesame: Identification of sesame oil and oil soot ink in organic deposits of Tang Dynasty lamps from Astana necropolis in China

Lamp illuminants evidence the exploitation of natural resources, animal and plant domestication, commerce, religious practices and nutrition of ancient populations. However, the physicochemical analysis of their major constituent—burned, degraded and aged mixture of triacylglycerols is imprecise and may lead to ambiguous interpretations. We applied proteomics to analyze fuel deposits from eight lamps dated by 6^th to 8^th centuries AD that were excavated at the Astana necropolis (Xinjiang, China) and determined their origin by identifying organism-specific proteins. Proteomics evidence corroborated and detailed the assignments of source organism relying upon comparative profiling of intact triacylglycerols by shotgun lipidomics. We found that ruminant (mostly, sheep) fat, cattle ghee and sesame oil were common combustibles in Astana and concluded that sesame as an oilseed appeared in China under Tang Dynasty concomitantly with the expansion of Buddhism.

Comportements alimentaires au Néolithique : nouveaux résultats dans le Bassin parisien à partir de l'étude isotopique (δ13C, δ15N) de la nécropole de Gurgy « Les Noisats » (Yonne, Vemillénaire av. J.-C.)

Les comportements alimentaires de la population néolithique de Gurgy « Les Noisats » (Yonne, Vemillénaire av. J.-C.) sont étudiés à travers l'analyse des ratios isotopiques du collagène osseux de 40 sujets. Cette nécropole correspond à l'une des plus importantes du Néolithique français : elle compte 126 inhumations primaires sur une période d'occupation de près d'un millénaire. Au cœur d'une région située à l'intersection entre plusieurs cultures, la grande diversité des dispositifs funéraires et du mobilier atteste des multiples influences alentour. Les résultats isotopiques (δ13C et δ15N) des humains comparés à la faune régionale soulignent l'importance des protéines animales issues de l'élevage (viande ou produits laitiers) — voire de poissons d'eau douce — dans le régime alimentaire. La très faible variation des valeurs enregistrée au sein de la population montre une grande homogénéité, rarement mise en évidence pour cette période, indiquant la consommation de ressources similaires pour l'ensemble des individus étudiés. La comparaison de ces données avec les paramètres biologiques et funéraires dégage toutefois quelques tendances, notamment en fonction de l'âge et du sexe des défunts, ainsi que de la chronologie.

Chemical Analysis of Pottery Demonstrates Prehistoric Origin for High-Altitude Alpine Dairying

The European high Alps are internationally renowned for their dairy produce, which are of huge cultural and economic significance to the region. Although the recent history of alpine dairying has been well studied, virtually nothing is known regarding the origins of this practice. This is due to poor preservation of high altitude archaeological sites and the ephemeral nature of transhumance economic practices. Archaeologists have suggested that stone structures that appear around 3,000 years ago are associated with more intense seasonal occupation of the high Alps and perhaps the establishment of new economic strategies. Here, we report on organic residue analysis of small fragments of pottery sherds that are occasionally preserved both at these sites and earlier prehistoric rock-shelters. Based mainly on isotopic criteria, dairy lipids could only be identified on ceramics from the stone structures, which date to the Iron Age (ca. 3,000-2,500 BP), providing the earliest evidence of this practice in the high Alps. Dairy production in such a marginal environment implies a high degree of risk even by today's standards. We postulate that this practice was driven by population increase and climate deterioration that put pressure on lowland agropastoral systems and the establishment of more extensive trade networks, leading to greater demand for highly nutritious and transportable dairy products.

Analytical Approaches Based on Gas Chromatography Mass Spectrometry (GC/MS) to Study Organic Materials in Artworks and Archaeological Objects

Gas chromatography/mass spectrometry (GC/MS), after appropriate wet chemical sample pre-treatments or pyrolysis, is one of the most commonly adopted analytical techniques in the study of organic materials from cultural heritage objects. Organic materials in archaeological contexts, in classical art objects, or in modern and contemporary works of art may be the same or belong to the same classes, but can also vary considerably, often presenting different ageing pathways and chemical environments. This paper provides an overview of the literature published in the last 10 years on the research based on the use of GC/MS for the analysis of organic materials in artworks and archaeological objects. The latest progresses in advancing analytical approaches, characterising materials and understanding their degradation, and developing methods for monitoring their stability are discussed. Case studies from the literature are presented to examine how the choice of the working conditions and the analytical approaches is driven by the analytical and technical question to be answered, as well as the nature of the object from which the samples are collected.

Gas-phase lithium cation basicity: revisiting the high basicity range by experiment and theory

According to high level calculations, the upper part of the previously published FT-ICR lithium cation basicity (LiCB at 373 K) scale appeared to be biased by a systematic downward shift. The purpose of this work was to determine the source of this systematic difference. New experimental LiCB values at 373 K have been measured for 31 ligands by proton-transfer equilibrium techniques, ranging from tetrahydrofuran (137.2 kJ mol(-1)) to 1,2-dimethoxyethane (202.7 kJ mol(-1)). The relative basicities (ΔLiCB) were included in a single self-consistent ladder anchored to the absolute LiCB value of pyridine (146.7 kJ mol(-1)). This new LiCB scale exhibits a good agreement with theoretical values obtained at G2(MP2) level. By means of kinetic modeling, it was also shown that equilibrium measurements can be performed in spite of the formation of Li(+) bound dimers. The key feature for achieving accurate equilibrium measurements is the ion trapping time. The potential causes of discrepancies between the new data and previous experimental measurements were analyzed. It was concluded that the disagreement essentially finds its origin in the estimation of temperature and the calibration of Cook's kinetic method.

Detection of synthetic testosterone use by novel comprehensive two-dimensional gas chromatography combustion-isotope ratio mass spectrometry

We report the first demonstration of comprehensive two-dimensional gas chromatography combustion-isotope ratio mass spectrometry (GC×GCC-IRMS) for the analysis of urinary steroids to detect illicit synthetic testosterone use, of interest in sport doping. GC coupled to IRMS (GCC-IRMS) is currently used to measure the carbon isotope ratios (CIRs, δ(13)C) of urinary steroids in antidoping efforts; however, extensive cleanup of urine extracts is required prior to analysis to enable baseline separation of target steroids. With its greater separation capabilities, GC×GC has the potential to reduce sample preparation requirements and enable CIR analysis of minimally processed urine extracts. Challenges addressed include online reactors with minimized dimensions to retain narrow peak shapes, baseline separation of peaks in some cases, and reconstruction of isotopic information from sliced steroid chromatographic peaks. Difficulties remaining include long-term robustness of online reactors and urine matrix effects that preclude baseline separation and isotopic analysis of low-concentration and trace components. In this work, steroids were extracted, acetylated, and analyzed using a refined, home-built GC×GCC-IRMS system. 11-Hydroxyandrosterone and 11-ketoetiocolanolone were chosen as endogenous reference compounds because of their satisfactory signal intensity, and their CIR was compared to target compounds androsterone and etiocholanolone. Separately, a GC×GC-quadrupole MS system was used to measure testosterone (T)/epitestosterone (EpiT) concentration ratios. Urinary extracts of urine pooled from professional athletes and urine from one individual that received testosterone gel (T-gel) and one individual that received testosterone injections (T-shots) were analyzed. The average precisions of δ(13)C and Δδ(13)C measurements were SD(δ(13)C) approximately ±1‰ (n = 11). The T-shot sample resulted in a positive for T use with a T/EpiT ratio of >9 and CIR measurements of Δδ(13)C > 5‰, both fulfilling World Anti-Doping Agency criteria. These data show for the first time that synthetic steroid use is detectable by GC×GCC-IRMS without the need for extensive urine cleanup.