Universal <sup>1</sup>H Spin–Lattice NMR Relaxation Features of Sugar—A Step towards Quality Markers
Hafiz Imran Fakhar,
Adam Kasparek,
Karol Kolodziejski,
Leonid Grunin,
Mecit Halil Öztop,
Muhammad Qasim Hayat,
Hussnain A. Janjua,
Danuta Kruk
Affiliations
Hafiz Imran Fakhar
Medicinal Plants Research Laboratory (MPRL), Department of Agricultural Sciences and Technology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), H-12, Islamabad 44000, Pakistan
Adam Kasparek
Department of Physics and Biophysics, University of Warmia and Mazury, 10-719 Olsztyn, Poland
Karol Kolodziejski
Department of Physics and Biophysics, University of Warmia and Mazury, 10-719 Olsztyn, Poland
Leonid Grunin
Resonance Systems GmbH, D-73230 Kirchheim unter Teck, Germany
Mecit Halil Öztop
Department of Food Engineering, Middle East Technical University, Ankara 06800, Turkey
Muhammad Qasim Hayat
Medicinal Plants Research Laboratory (MPRL), Department of Agricultural Sciences and Technology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), H-12, Islamabad 44000, Pakistan
Hussnain A. Janjua
Department of Industrial Biotechnology, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad 44000, Pakistan
Danuta Kruk
Department of Physics and Biophysics, University of Warmia and Mazury, 10-719 Olsztyn, Poland
1H fast field-cycling and time-domain nuclear magnetic resonance relaxometry studies have been performed for 15 samples of sugar of different kinds and origins (brown, white, cane, beet sugar). The extensive data set, including results for crystal sugar and sugar/water mixtures, has been thoroughly analyzed, with a focus on identifying relaxation contributions associated with the solid and liquid fractions of the systems and non-exponentiality of the relaxation processes. It has been observed that 1H spin–lattice relaxation rates for crystal sugar (solid) vary between 0.45 s−1 and 0.59 s−1, and the relaxation process shows only small deviations from exponentiality (a quantitative measure of the exponentiality has been provided). The 1H spin–lattice relaxation process for sugar/water mixtures has turned out to be bi-exponential, with the relaxation rates varying between about 13 s−1–17 s−1 (for the faster component) and about 2.1 s−1–3.5 s−1 (for the slower component), with the ratio between the amplitudes of the relaxation contributions ranging between 2.8 and 4.2. The narrow ranges in which the parameters vary make them a promising marker of the quality and authenticity of sugar.
