PhD defence by Elnora Abdullajeva

Principal supervisor:

• Associate Professor Lene Duedahl-Olesen

Co-supervisor:

• Associate Professor Elena Hakme

Examiners:

• Associate Professor Ditte Baun Hermund, National Food Institute,  DTU
• Professor Joaquin Beltran Arandes, Analytical Chemistry Research Group, Jaume I University, Spain
• Professor Trine Kastrup Dalsgaard, Department of Food Science, Aarhus University.

Moderator at defence:

• Professor Jens Jørgen Sloth

Resume
Plant-based meat alternatives constitute an emerging food category that has been evaluated from multiple perspectives, including nutritional composition and sustainability. However, their globally sourced composite formulation, together with high-temperature extrusion processing distinguishes them from other food groups. Several authors have proposed that this combination may alter consumer exposure to a range of chemical hazards as dietary patterns shift towards increased consumption of these products. The current thesis addresses this hypothesis through a multi-domain chemical safety characterization, applying targeted and non-targeted analytical methods and risk assessment principles at varying levels of evidence across four hazard domains.

Firstly, processing contaminants generated through thermal processing were investigated. Among these were acrylamide, typical for carbohydrate-rich foods and characterized as probable carcinogen, and heterocyclic aromatic amines (HAAs) and N-nitrosamines (NAs) ubiquitous in meat products and regarded as main contributors towards carcinogenicity of processed conventional meat products. Quantification of these analytes enabled full risk assessment via margin of exposure at various consumption scenarios. From food safety perspective, HAAs and NAs in plant-based meat alternatives presented more favorable profiles than in conventional meats, whereas exposure to acrylamide in high-consumption scenarios indicated potential concern. The investigation was later extended for analysis of chemicals beyond anticipated contaminants, identifying multiple compounds previously not characterized in these types of samples by applying a non-targeted GC-Orbitrap workflow. Several were assigned high-priority status through hazard prioritization framework due to genotoxicity and carcinogenicity records, warranting future follow-up.

Direct in-sample analysis method was developed for polyethylene terephthalate (PET) oligomers, low molecular weight unreacted or partially reacted building blocks of PET packaging, capable of migrating into foods. This approach aimed at bypassing overestimation bias inherent to simulant-based analysis. Analysis of real plant-based alternative samples has shown that occurrence levels were low, with most measurements below quantification limits under tested conditions. Finally, pesticide residues were screened, with generally low levels detected post-processing.

Measurable chemical safety signals were identified across all four domains, though the strength of evidence varied by domain, constrained in part by the absence of EU-specific regulatory thresholds for this food category. Collectively, the findings do not indicate acute safety concerns under current market conditions but highlight a characterization challenge rather than a systematic exposure increase relative to conventional meat. The methodological contributions, namely the non-targeted GC-Orbitrap workflow and the direct PET analysis method, address analytical limitations that previously constrained chemical safety assessment of compositionally complex food matrices, supporting future occurrence monitoring and risk assessment.

A copy of the PhD thesis is available for reading at the department.