Establishment of novel standardised operating procedures for LF‐NMR: used in rapid detection of typical fruit and vegetable

Abstract

SummaryAlthough LF‐NMR has been widely used in many fields of food science, the lack of NMR expertise of many food researchers needs to be bridged. Using samples of carrots, bananas, and king oyster mushroom, this work systematically studied the influence of LF‐NMR parameters (repetition time (TR), echo time (TE)) on experimental results. The result showed that the TR of carrot, mushroom and banana were 2684, 4572 and 4317 ms, respectively. The rate of change of signal amplitude can be used as an index to optimise TR. The change of TE has different effects on the short relaxation components of the T2 distributions and long relaxation components in different TR samples. TE and Nech should be set according to T2 to record completely the decay process. What’s more, the method of normalised CPMG decay was suggested to eliminate the effects of parameters such as number of scan (NS), pre‐amp regulate gain (PRG) and mass of sample. At last, the standardised operating procedures were proposed to provide a strategy of improving the properties and applications of LF‐NMR.