Processes of Thermal Treatment on Hazelnuts Investigated by NMR and MRI
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View abstract on PubMed
Summary
This summary is machine-generated.Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) monitored hazelnut roasting. High temperatures destroyed oil-containing structures and initiated oil oxidation, impacting product quality.
Area Of Science
- Food Science and Technology
- Analytical Chemistry
- Materials Science
Background
- Hazelnuts have a high oil content crucial for quality and shelf life.
- Thermal processing, like roasting, can negatively impact hazelnut oil stability and structure.
- Understanding these changes is vital for optimizing processing and ensuring product quality.
Purpose Of The Study
- To monitor structural and compositional changes in hazelnuts during thermal treatment using NMR and MRI.
- To investigate the roasting and aging behavior of hazelnut oil.
- To correlate changes across molecular, micro-, and mesostructural levels.
Main Methods
- In situ Magnetic Resonance Imaging (MRI) for mesostructural analysis (50 μm - mm).
- Pulsed Field Gradient Stimulated Echo (PFG-STE) NMR diffusion experiments for microstructural analysis (100 nm - 10 μm).
- NMR spectroscopy for molecular-level analysis of oil oxidation.
Main Results
- MRI revealed significant void formation and cellular collapse at 200°C during roasting.
- PFG-STE NMR showed oleosome destruction at 100°C and altered oil mobility.
- NMR spectroscopy indicated temperature-dependent oxidation of unsaturated fatty acids in hazelnut oil.
Conclusions
- Combined MRI and NMR enable quasi-nondestructive, in situ monitoring of hazelnut transformations during thermal processing.
- Thermal stress significantly alters hazelnut microstructure and oil composition, affecting quality.
- These techniques provide valuable insights into hazelnut oil behavior under processing conditions.
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