NMR Spectroscopy Protocols for Food Metabolomics Applications
Evangelia Ralli1, Maria Amargianitaki1, Efi Manolopoulou1
1NMR Laboratory, Chemistry Department, University of Crete, Heraklion, Crete, Greece.
Methods in Molecular Biology (Clifton, N.J.)
|April 15, 2018
Summary
Nuclear Magnetic Resonance (NMR) spectroscopy offers a versatile method for food metabolic profiling. This study details an NMR approach for analyzing polar and nonpolar metabolites in diverse food types like wine, cheese, and coffee.
Area of Science:
- Analytical Chemistry
- Food Science
- Biochemistry
Background:
- Metabolic profiling is crucial for understanding food composition and quality.
- Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful, non-destructive technique for analyzing complex biological samples.
- Existing NMR protocols may require adaptation for the diverse matrices found in food products.
Purpose of the Study:
- To present a standardized liquid-state Nuclear Magnetic Resonance (NMR) spectroscopy protocol for the metabolic profiling of various food products.
- To demonstrate the adaptability of the protocol for both liquid and solid food matrices.
- To facilitate the comprehensive analysis of polar and nonpolar metabolites in foodstuffs.
Main Methods:
- Liquid-state Nuclear Magnetic Resonance (NMR) spectroscopy was employed.
- The protocol was applied to common food items including wine, spirits, juice, cheese, coffee, and honey.
- Methodologies were designed for the determination of both polar and nonpolar metabolites.
Main Results:
- The developed NMR approach successfully determined polar and nonpolar metabolites in diverse food samples.
- The protocol proved effective for common liquid foods (wine, spirits, juice) and solid foods (cheese, coffee, honey).
- Minor modifications allowed for the adaptation of the protocol across different food types.
Conclusions:
- Liquid-state NMR spectroscopy provides an effective strategy for the metabolic profiling of a wide range of food products.
- The presented protocol is adaptable, offering a flexible tool for food analysis.
- This methodology supports advancements in food quality assessment and characterization through detailed metabolic insights.
Related Concept Videos
01:19NMR Spectroscopy Of Amines
11.2K
In proton NMR spectroscopy, primary amines and secondary amines showcase their N–H protons as a broad signal in the chemical shift range between δ 0.5 and 5 ppm. The exact position in this range depends on several factors, including sample concentration, hydrogen bonding, and the type of solvent used. Since amine protons undergo fast proton exchange in solution, the protons are labile and therefore do not participate in any splitting with adjacent protons. Thus, the observed peak is...
11.2K
01:25Applications Of NMR In Biology
4.5K
Nuclear magnetic resonance (NMR) spectroscopy is a very valuable analytical technique for researchers. It has been used for more than 50 years as an analytical tool. F. Bloch and E. Purcell formulated NMR in 1946 and won the 1952 Nobel Prize in Physics for their work. Biological macromolecules such as proteins, nucleic acids, lipids, and organic molecules including pharmaceutical compounds, can be studied using this versatile tool that exploits the magnetic properties of certain nuclei.
4.5K
01:14NMR Spectroscopy of Aromatic Compounds
6.4K
Aromatic compounds can be identified or analyzed using proton NMR and carbon‐13 NMR. Typically, aromatic hydrogens or hydrogens directly bonded to the aromatic rings are strongly deshielded by the aromatic ring current. Therefore, they absorb in the range of 6.5–8.0 ppm in proton NMR spectra. For instance, aromatic hydrogens directly bonded to the benzene ring absorb at 7.3 ppm. However, aromatic hydrogens of larger rings absorb farther upfield or downfield than the ideal range.
6.4K
01:34NMR Spectroscopy of Benzene Derivatives
11.3K
Simple unsubstituted benzene has six aromatic protons, all chemically equivalent. Therefore, benzene exhibits only a singlet peak at δ 7.3 ppm in the 1H NMR spectrum. The observed shift is far downfield because the aromatic ring current strongly deshields the protons. Any substitution on the benzene ring makes the aromatic protons nonequivalent, and the protons split each other. The peak is, therefore, no longer a singlet and the splitting pattern and their associated coupling...
11.3K
01:15NMR Spectroscopy: Chemical Shift Overview
3.4K
The position of the absorption signal of a sample is reported relative to the position of the signal of tetramethylsilane (TMS), which is added as an internal reference while recording spectra. The difference between the absorption frequencies of the sample and TMS (in Hz) is divided by the spectrometer operating frequency (in MHz) to obtain a dimensionless quantity called the chemical shift. It is reported on the δ (delta) scale and expressed in parts per million.
For instance, the proton...
For instance, the proton...
3.4K
01:08NMR Spectroscopy: Spin–Spin Coupling
3.3K
The spin state of an NMR-active nucleus can have a slight effect on its immediate electronic environment. This effect propagates through the intervening bonds and affects the electronic environments of NMR-active nuclei up to three bonds away; occasionally, even farther. This phenomenon is called spin–spin coupling or J-coupling. Coupling interactions are mutual and result in small changes in the absorption frequencies of both nuclei involved. While nuclei of the same element are involved...
3.3K