Utilising phytanic acid diastereomers for the characterisation of archaeological lipid residues in pottery samples

Alexandre Lucquin,André C Colonese,Thomas F.G Farrell,Oliver E Craig

doi:10.1016/j.tetlet.2016.01.011

Alexandre Lucquin, André C Colonese + Show 2 more

Open Access

https://doi.org/10.1016/j.tetlet.2016.01.011

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Abstract

Phytanic acid diastereomers, 3S,7R,11R,15-phytanic acid (SRR) and 3R,7R,11R,15-phytanic acid (RRR), were determined by GC–MS in extracts of archaeological ceramic. The SRR% was higher in pottery from coastal sites corresponding with 13C enriched n-alkanoic acid corroborating a predominantly marine origin for the food residues. Conversely, low SRR% and 13C depleted n-alkanoic acid were found at inland sites, which are most likely derived from ruminant products. These observations are explained by differences in the bacterial transformation of phytol to phytanic acid between ruminant and aquatic organisms and allow these products to be easily distinguished in archaeological contexts.

Highlights

Molecular and stable isotope analyses of organic residues preserved in archaeological pottery provide valuable insights into the cooking practices and diet of past societies, and have become pivotal to the investigation of economic and cultural changes in the past
A wide range of analytical procedures have been applied to characterise ancient biomolecules in pottery vessels but in recent years, gas chromatography mass spectrometry (GC– MS) and gas chromatography combined with isotope ratio mass spectrometry (GC-C-IRMS)[1,2] have become the methods of choice
We investigate the utility of using phytanic acid diastereomers recovered from archaeological pottery as a novel biomarker to distinguish aquatic and ruminant products

Summary

Introduction

Molecular and stable isotope analyses of organic residues preserved in archaeological pottery provide valuable insights into the cooking practices and diet of past societies, and have become pivotal to the investigation of economic and cultural changes in the past. A wide range of analytical procedures have been applied to characterise ancient biomolecules in pottery vessels but in recent years, gas chromatography mass spectrometry (GC– MS) and gas chromatography combined with isotope ratio mass spectrometry (GC-C-IRMS)[1,2] have become the methods of choice These techniques have been routinely used to discriminate various mammal fats,[3] fish oils,[4,5] dairy products[6,7] and edible plants[8] based on the identification of lipid biomarkers and/or the isotopic criteria of less diagnostic compounds, such as n-alkanoic acids. Phytanic acid is frequently found in archaeological cooking vessels, distinguishing its origin maybe extremely important in the absence of other more diagnostic compounds

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