During his PhD studies, Ivan Misael Lopez Rodulfo investigated the key factors governing polyphenol bioaccessibility during gastrointestinal digestion and their influence on glucose metabolism. Using apples as a dietary model, he employed high-resolution mass spectrometry to systematically characterize polyphenol profiles and their transformations. His work elucidated how the food matrix dictates polyphenol partitioning during both conventional cold-pressing for juice production and gastrointestinal digestion. Through rigorous standardization of in vitro digestion protocols, his research further revealed the specific role of both pancreatic and brush border enzymes in remodeling polyphenol profiles via linkage-specific deglycosylation. By connecting these bioaccessibility dynamics to glucose metabolism, he demonstrated how bioaccessible polyphenol fractions modulate intestinal glucose transport and enhance secretion of GLP-1, a pivotal incretin hormone involved in glycemic regulation.

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: Wednesday, 25 June 2025 at 13:00
Place: Meeting room 5910-214, Department of Food Science, Aarhus University, Agro Food Park 48, 8200 Aarhus N
Title of PhD thesis: In vitro bioaccessibility and metabolic effects of polyphenols from different apple matrices in the upper gastrointestinal tract   
Contact information: Ivan Misael Lopez Rodulfo, e-mail: imlopez@food.au.dk, tel.: +45 41 89 33 27
Members of the assessment committee:
Professor Lilian Barros, Mountain Research Center (CIMO), Polytechnic Institute of Bragança, Portugal
Lecturer Alan Javier Hernandez Alvarez, School of Food Science and Nutrition, University of Leeds, United Kingdom
Professor Marianne Hammershøj (chair), Department of Food Science, Aarhus University, Denmark
Main supervisor: Associate Professor Mario Martinez Martinez, Department of Food Science, Aarhus University, Denmark
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.