[Thesis defence] 10/12/2025 – Lindsay Mas-Normand: «New analytical developments for metabolomics and the annotation of dye plant extracts: Applications in a cultural heritage context» (UMR IMBE)

Ms Lindsay MAS will publicly defend her thesis entitled: «New analytical developments for metabolomics and the annotation of dye plant extracts: Applications in a cultural heritage context» supervised by Mr Gérald CULIOLI, Ms Carole MATHE and Mr Olivier DANGLES, on Wednesday 10 December 2025.

Laboratory

UMR 7263 IMBE - Mediterranean Institute of Biodiversity and Ecology EECAR

Composition of the jury

Mr Gérald CULIOLI	Avignon University	Thesis supervisor
Ms Émilie DESTANDAU	University of Orléans	Rapporteur
Ms Carole MATHE	Avignon University	Thesis co-director
Mr Olivier DANGLES	Avignon University	Thesis co-director
Ms Audrey LE GOUELLEC	Grenoble Alpes University	Rapporteur
Mr Joël BOUSTIé	University of Rennes 1	Examiner
Mr Thibaut DEVIÈSE	Aix Marseille University	Examiner

Summary

Natural dyes were used by humans to dye fabrics and various everyday objects until the end of the 19th century. Today, historians, museum curators and scientists are attempting to unravel the secrets of heritage objects in order to better understand their history and preserve them more effectively. Thanks to the data collected, it is sometimes possible to trace the techniques and materials used in their dyeing, or the exchange of raw materials and know-how. A wide range of analytical techniques can be used to obtain such information. However, it is often difficult to trace the exact botanical origin of the natural dyes identified in an object, particularly in the case of the colour yellow. This colour can be obtained from a wide variety of dye plants, and many compounds are commonly found in several of them. In order to propose a method for accurately identifying the botanical origin of the dyes used to dye heritage objects, but also to better characterise the impact of dyeing and degradation conditions on their dye molecule compositions, a non-targeted metabolomic approach is proposed as part of this thesis work. Metabolomics has already proven its worth in studies on environmental stress, the discovery of biomarkers and the search for bioactive molecules, but its use in heritage chemistry remains anecdotal. The first objective of this thesis was to develop an untargeted metabolomic approach, using LC-HRMS/MS and annotation tools such as molecular networks, in order to determine specific chemical markers for a selection of yellow dye plants. The second objective was to study the stability and degradation of dye molecules, depending on the dyeing conditions, the conservation of the object and the extraction methods used. Finally, the third objective was to apply the method developed to ancient objects and to see if it was possible to find some of the chemical markers described in the first two objectives.

Keywords Analytical chemistry, Metabolomics, Mass spectrometry, Dye plant, Archaeometry, Dye