Lipids as carriers of anthropogenic signals from prehistory

Abstract

Studies performed during the last two decades have shown that lipids are preserved in association with a wide range of artefacts and ecofacts recovered from archaeological sites, e.g. pottery vessels and skeletal remains. The majority of work in this area has focused on the use of molecular structures (`biomarkers') and distributions (`¢ngerprints') to assess the nature and origin of commodities associated with past cultural, economic and agricultural practices. However, since lipids, like all other classes of biomolecule, are a¡ected by degradation (both pre-and post-burial), emphasis is now being placed on the complementary use of diagenetically robust, compound-speci¢c stable isotope measurements to enhance the scope and reliability of archaeological interpretations. A feature of the 13 C values of individual lipids, rather than bulk measurements of biochemically more heterogeneous materials, lies in their capacity to re£ect di¡erences in both the isotopic composition of the carbon sources used in their biosynthesis and the routing of dietary lipids and their metabolites in consumer organisms. This isotopic information, accessible by gas chromatography^combustion-isotope ratio mass spectrometry, has opened up new avenues of investigation concerning human activity in prehistory.

Organic Residues in Archaeology: The Highs and Lows of Recent Research

“…They include residues of foods and other materials in pottery, residues left on stone tools during use, substances used in mummification, residues left in plaster floors by human activities, pastes and glues used in the construction of artworks and other artefacts, binders used to apply colour to paintings and statues, organic colourants used on textiles, organic material preserved in the mineral matrix of bone, and even the remains of ancient manures found in soils (3). Their analysis can inform us about trade, technology, diet, medicine, cosmetics, arts, crafts, farming practices, how people organized their houses and how they prepared their dead for burial (3,(6)(7)(8).…”

“…However, the increasing importance of isotopic analysis of various types of materials raises the question of whether isotopic values are stable under burial conditions. Two studies in the late 1990s measuring the carbon isotopic values (δ 13 C) of stearic and palmitic acids before and after simulated burial in oxic and anoxic environments showed that, under these conditions, isotopic values remained robust (4,7,31). It has also been shown that the changes in hydrogen isotopic values (δD) of individual fatty acids caused by cooking followed by burial for 16 months are significantly less than the natural variation in δD of fatty acids from a range of animal fats (32).…”

Arqueologia biomolecular: passos preliminares para interpretações sobre a origem dos resíduos orgânicos preservados em fragmentos de cerâmica pré-colonial no Brasil

“…Nos últimos 30 anos, através das técnicas de cromatografia gasosa (GC) e cromatografia gasosa acoplada à espectrometria de massas (GC-MS), a caracterização dos lipídios preservados em fragmentos de cerâmica possibilitou identificar o processamento de vários tipos de produtos com origem animal e vegetal (gorduras animais, óleos vegetais, resinas e ceras) 3,4 . A presença de triterpenos, ésteres de cadeias longas (Es 20:0 -Es 60:0 ) e fitoesteróis são indicativos de contribuição vegetal.…”

A review of current applications of mass spectrometry for biomarker/molecular tracer elucidations

“…For example, it can document past agricultural practices, decipher embalming agents, assess food intake in coprolites, or determine contents of pottery vessels (Dudd & Evershed, 1998;Evershed et al, 1999Evershed et al, , 2002Buckley & Evershed, 2001;Copley et al, 2001;Bull et al, 2002).…”