Current applications of benchtop FT-NMR in food science. From quality control to adulteration detection

The introduction of benchtop FT-NMR spectrometers in recent years represents a remarkable innovation in various fields, including the food sector. Modern benchtop FT-NMR spectrometers are low-field instruments, with a magnetic field ranging from 1 T to 2.35 T (1H resonance frequency from 43 MHz to 100 MHz), characterized by compact design, ease of use, and low maintenance costs. As in the case of high-field NMR instruments, benchtop NMR spectra (obtained by Fourier transformation) contain important information useful for compound identification and quantification. In this review, a description of the fundamental steps useful both to acquire benchtop NMR spectra and to treat the obtained data is reported together with a wide range of applications in the food field. In particular, peculiar aspects of commercial benchtop instruments as well as NMR data acquisition, processing and treatment are reviewed reporting also a practical pipeline and a list of good practices for benchtop NMR applications. Benchtop FT-NMR applications, mainly focused on food adulteration detection and quality control, are discussed here using targeted, metabolomic, and fingerprinting approaches. Finally, the industrial applicability of benchtop NMR methods in either static or continuous mode is reported.