During his PhD studies, Kasper Brandhøj Skov focused on converting stale bread, a significant contributor to food waste, into functional bioplastics. He investigated the acetylation of bread starch using deep eutectic solvents (DES), offering a more sustainable alternative to traditional methods. Results showed that choline chloride (ChCl):urea is an ideal chaotropic solvent for this reaction since it was not only capable of completely solubilizing starch but also provided a favorable environment for the synthesis of esterified starches. Expanding from these findings, combinations of reaction time, temperature, and acetic anhydride ratio were explored to acetylate macromolecules within bread particles. Finally, the impact of citric acid on the properties of films derived from stale bread was investigated, comparing films fabricated via solvent casting and extrusion/hot-pressing techniques.

Kasper's research demonstrates the potential of stale bread as a sustainable resource, contributing to the development of eco-friendly materials and offering innovative solutions for reducing food waste.

The PhD study was completed at Department of Food Science, Faculty of Technical Sciences, Aarhus University.

This summary was prepared by the PhD student.

Time: Thursday, 3^rd of April 2025 at 13:00
Place: Building 5910, room 116, Lecture Theatre, Department of Food Science, Aarhus University, Agro Food Park 48, 8200 Aarhus N
Title of PhD thesis: Green esterification of pure starch and stale bread particles for thermoplastic applications
Contact information: Kasper Brandhøj Skov, e-mail: kbs@food.au.dk, tel.: +45 29417371
Members of the assessment committee:
Professor Chelo Gonzalez Martinez, School of Agricultural Engineering and Environment, Universitat Politecnica of Valencia, Spain
Professor Daniel Wefers, Institute of Food Chemistry, Martin Luther University Halle-Wittenberg, Germany
Professor Carl-Otto Ottosen,(chair), Department of Food Science, Aarhus University, Denmark
Main supervisor:
Associate Professor Mario Martinez-Martinez, Department of Food Science, Aarhus University, Denmark
Co-supervisor:
No Co-supervisor
Language: The PhD dissertation will be defended in English

The defence is public.
The PhD thesis is available for reading at the Graduate School of Technical Sciences/GSTS, Ny Munkegade 120, building 1521, 8000 Aarhus C.