Dissertation defence (Food Development): MSc Yuqing Zhang
Time
19.5.2025 at 12.00 - 16.00
MSc Yuqing Zhang defends the dissertation in Food Development titled “Structural Analysis of Triacylglycerols and Bioavailability of Docosahexaenoic Acid from Regio- and Enantiopure Triacylglycerols” at the University of Turku on 19 May 2025 at 12.00 (University of Turku, Medisiina C, Osmo Järvi lecture hall, Kiinamyllynkatu 10, Turku).
Opponent: Professor Zheng Ouyang (Tsinghua University, China)
Custos: Professor Baoru Yang (University of Turku)
The audience can participate in the defence by remote access: https://utu.zoom.us/j/67878607965 (meeting ID: 678 7860 7965)
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Summary of the Doctoral Dissertation:
Triacylglycerols (TG) and glycerophospholipids (GPL) are essential lipid molecules found in food and play vital roles in human physiology. The diversity of fatty acids (FAs) and the presence of structural isomers cause significant challenges to their structural analysis. In natural samples, the distribution of FAs on the glycerol backbone is not random, and the properties of isomers can vary considerably despite structural similarities. These structural variations can affect the physical properties or nutritional significance of fats and oils, such as the melting point and bioavailability of TGs and GPLs.
This thesis focuses on the structural analysis of TGs and the investigation of the bioavailability of FAs in synthesized TGs. Using synthesized compounds, the research begins with a comprehensive study of the chiral chromatographic separation of TG enantiomers. This study enhanced the understanding of the chiral chromatographic retention behavior and elution order of TG enantiomers.
The second part of this thesis investigated the nutritional and biological implications of fatty acyl positional isomers of TGs through an animal trial by exploring how the positional distribution of docosahexaenoic acid (DHA) in TGs influences the bioavailability and metabolic fate of DHA. This study provides fresh insights into the impact of the positional distribution of DHA in dietary TGs and GPL profiles in rat organs for the first time. Furthermore, this research is the first to demonstrate that n-3 PUFA-deficient diet altered GPL molecular species composition in organs, and DHA supplementation counteracts these changes.
In conclusion, this thesis offers valuable contributions to understanding the composition and metabolism of chiral TGs, from analytical methodologies to biological evaluation. The study provides critical insights into the chromatographic behavior of TG enantiomers and highlights the impact of FA positional distribution on lipid chemistry and biology. These findings serve as foundational references for future studies of natural lipids.
Opponent: Professor Zheng Ouyang (Tsinghua University, China)
Custos: Professor Baoru Yang (University of Turku)
The audience can participate in the defence by remote access: https://utu.zoom.us/j/67878607965 (meeting ID: 678 7860 7965)
***
Summary of the Doctoral Dissertation:
Triacylglycerols (TG) and glycerophospholipids (GPL) are essential lipid molecules found in food and play vital roles in human physiology. The diversity of fatty acids (FAs) and the presence of structural isomers cause significant challenges to their structural analysis. In natural samples, the distribution of FAs on the glycerol backbone is not random, and the properties of isomers can vary considerably despite structural similarities. These structural variations can affect the physical properties or nutritional significance of fats and oils, such as the melting point and bioavailability of TGs and GPLs.
This thesis focuses on the structural analysis of TGs and the investigation of the bioavailability of FAs in synthesized TGs. Using synthesized compounds, the research begins with a comprehensive study of the chiral chromatographic separation of TG enantiomers. This study enhanced the understanding of the chiral chromatographic retention behavior and elution order of TG enantiomers.
The second part of this thesis investigated the nutritional and biological implications of fatty acyl positional isomers of TGs through an animal trial by exploring how the positional distribution of docosahexaenoic acid (DHA) in TGs influences the bioavailability and metabolic fate of DHA. This study provides fresh insights into the impact of the positional distribution of DHA in dietary TGs and GPL profiles in rat organs for the first time. Furthermore, this research is the first to demonstrate that n-3 PUFA-deficient diet altered GPL molecular species composition in organs, and DHA supplementation counteracts these changes.
In conclusion, this thesis offers valuable contributions to understanding the composition and metabolism of chiral TGs, from analytical methodologies to biological evaluation. The study provides critical insights into the chromatographic behavior of TG enantiomers and highlights the impact of FA positional distribution on lipid chemistry and biology. These findings serve as foundational references for future studies of natural lipids.
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