With National Science Foundation support, Dr Steve Wolverton and a team of archaeologists, analytical chemists, and proteomic biologists will do burial experiments with modern cooking pottery and research on archaeological pottery to evaluate the role of variability in climate, soil, and ceramic paste on the preservation of food protein residues. This project builds on previous research funded by NSF in which the same team addressed which types of solvents and physical conditions work best for extraction of protein residues from cooking pottery. Protein residues offer distinctive advantages over other types of food residues in that they bind to clay in pottery walls, which enhances preservation, and that proteins can often be identified to species or perhaps even to tissue. An important hurdle is that factors that mediate long-term preservation of protein residues have not been well studied, the focus of this project in both experimental and archaeological settings.
This research is important because it will provide a new set of tools which will allow archaeologists to examine previously inaccessible aspects of past culture. It will help to reconstruct past subsistence patterns and provide insight into how populations adapted to the environments in which they lived.
Residue analysis in general has lacked for detailed studies of method development. In terms of intellectual merit, the high potential of protein residues to provide precise data on what people cooked in pots in the past makes experimental replication of methods an essential process. Production of reliable analytical approaches and knowledge of conditions in which proteins are more and less likely to preserve will greatly amplify or current knowledge of protein residues from ancient foods.
This project involves students and professionals from Argentina and the United States, from a museum (Argentina), a non-profit public-education/archaeological research firm (US), and universities (US). The nature of the work is highly interdisciplinary, incorporating professionals with specialties in archaeology, ceramic petrography, material science, chemistry, and biology. The project will fund a graduate student for two academic years to work with this interdisciplinary team. Results will be published in scholarly journals and will be presented at academic conferences and in classroom settings.
This NSF-funded project brought together an interdisciplinary team of archaeologists and chemists to investigate how proteins bind to ceramic material (pottery) and to determine the best approach to isolate and detect proteins from experimental cooking pottery as well as archaeological artifacts. The results from this project build on previous work from the same team in which an unbiased analytical approach using a technique called mass spectrometry was optimized for protein residue analysis. First, a method for protein extraction from experimental pottery was developed and implemented in combination with a new sample clean-up approach recently described for the analysis of biological samples (cells and animal tissue). The sample processing allowed for efficient sample cleaning which is critical prior to analysis by mass spectrometry. Second, representative food stuffs were cooked onto experimental cooking pottery and the optimized sample processing methods were then employed. Detailed protein lists were generated which facilitated selection of potential protein "markers" that would allow for identification of food source (e.g., animal versus plant protein) upon analysis of archaeological cooking pottery. Further development of these markers also allowed for more specific identification of protein source through targeted analysis by mass spectrometry. The activities from this project resulted in graduate student training in cutting-edge protein analysis techniques and enhanced undergraduate education through classroom presentation of selected results from this project. The broader impacts of this project include the development of a novel workflow for the analysis of protein residue that incorporates both unbiased and targeted analytical approaches. In archaeology, the characterization of protein residues from ancient cooking pottery provides information about how the pottery was used and how this use evolved over time in various places and corresponding time periods in the world. The methodology, however, can be adapted to other applications in archaeology as well as other disciplines such as forensics in which protein residue characterization would be valuable.