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Rapid NMR determination of inorganic cations in food matrices: Application to mineral water النص الكامل
2017
Monakhova, Yulia B. | Kuballa, Thomas | Tschiersch, Christopher | Diehl, Bernd W.K.
A nuclear magnetic resonance (NMR) method was developed to quantify cations in mineral water. The procedure was based on integration of signals from metal-ethylenediaminetetraacetic acid (EDTA) complexes at δ 2.70ppm for Mg2+ and δ 2.56ppm for Ca2+. The limits of detection were below 0.5mg/L. Lack of precision did not exceed 5%. Linearity was between 1 and 500mg/L. Correlation between NMR and a reference chromatographic method was significant (p<0.0001, R2=0.99). PLS models were also established to estimate Na+ and K+ contents. R2 was 0.85 and 0.83, respectively. Root mean square errors of cross validation (RMSECV) were 8.0mg/L and 1.9mg/L for Na+ and K+, respectively. The method was applied successfully for the analysis of 31 mineral water samples. This method is a useful tool for quantification of important cations in mineral water and might easily be adapted to other food matrices.
اظهر المزيد [+] اقل [-]Measurement of water movement in food and biomaterials by pulsed field gradient (PFG)-NMR
2005
Hong, Y.P.(Korea Univ., Seoul (Korea R.)) | Lee, C.H.
Pulsed-field gradient NMR (PFG -NMR) is widely applied to probe living tissues and biological cells structure for measuring thermodynamic binding constants, membrane permeability and rates of transmembrane exchange processes. Water movements in biological systems and food matrices are important in the engineering aspect such as quality manipulation in food processing. The measurement of diffusion properties of water molecules in food systems is now possible using PFG -NMR, and the hydration properties and hydrodynamic properties of food materials can be accurately evaluated by this method. In this paper, we measured the diffusion behavior of water in protein matrix, Tofu, and the membrane permeability in biological cell such as chlorella, yeast and human red blood cell non-invasively by PFG-NMR.
اظهر المزيد [+] اقل [-]