Analysis of amino acids in foodstuff by Nuclear Magnetic Resonance

The analysis of amino acids in foodstuff was carried out by Nuclear Magnetic Resonance (NMR). The ¹H NMR, ¹³C NMR and 2D NMR (HSQC) were applied for qualitative study, and inverse-gated-decoupling ¹³C NMR was used for quantitative study. The relative standard deviation was between 0.65%~3.59% (n = 6). The range of linearity was over two orders of magnitude for most amino acids. In the analysis of Spirulina and Mushroom, automatic amino acid analyzer was used too. Comparing results from NMR and amino acid analyzer, the relative error in content of amino acids was less than 5%. Results show this new NMR method can be applied in both qualitative and quantitative analyses for the great mass of amino acids in foodstuff.