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Introduction

Ceramic vessels together with visible charred foodremains (so-called foodcrusts) allow detecting the contents of ancient vessels and offer valuable insights into ancient foodways and economy. Foodcrusts can be subject to lipid residue,bulk stable isotope,proteomic, and microfossil analysis. Food-related biomolecules and microremains also absorb into ceramic surfaces, with the lipids, owing to their hydrophobic and relatively stable nature, being the most preserved. Consequently, ceramic matrices are predominantly analysedfor lipid residues using various mass-spectrometry methods, but can also reveal some microfossil records. 

The quantity of sample required for successful analysis varies depending on the methodology. Below are rough estimations of required samples as per the analytical method: 

1. microfossil analysis –1 mg of foodcrust, 
2. Proteomic analysis – 10 mg of foodcrust, 
3. bulk stable isotopeanalysis(with EA-IRMS) – ca 5 mg offoodcrust;
4. lipid residue analysis, ca 20 mg foodcrust; at least 0.5 g of homogenised ceramic powder for acid extraction, and around 1 g for solvent extraction.

Proteomics Data Workflow  

Lipid Data Workflow

Proteomics Data Workflow  

Data Acquisition and Export 

Data Processing with LC-MS 

Analysis Scripts and Computational Tools (MaxQuant, MetaMorpheus 

Lipid Data Workflow

In lipid analysis we usually have three steps of workflow generating a series of raw data -> interpreted data -> integrated data. 

• Data Acquisition and Export (GC-FID, GC-MS, GC-SIM, GC-C-IRMS) 

GC-FID and GC-MS (scan and SIM) data is generated by masshunter software. 

For example, there is a sequence of measurements. 

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Each measurement will generate a folder containing a series of raw data (method acquisition file and data files). 

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GC-C-IRMS data is generated by Qtegra. 
Each sequence produces a single container file (.imexp) that contains all the measurement data. It is not possible to extract individual measurements from this file. The .imexp format can only be opened with Qtegra® software.

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After initial checks and corrections in Qtegra®, the relevant data is exported to .xlsx format for calibration and for general accessibility.

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It's also possible to export all chromatogram data points, allowing graphs to be reconstructed in Excel (.xlsx) or ohter programs as well. 

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Data reliability/limitation of method 

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Microfossil Data Workflow

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