A noninvasive LF‐NMR method was developed to monitor proton dynamics on caviar stored at −4°C for 11 months. T2 relaxation spectra revealed three peaks at 0.54–0.75, 20.61–30.78, and 147.24–307.37 ms, respectively, whereas T1 showed only one peak around 167.16–217.31 ms. The T21 and T22 components remained unchanged during the storage period, while T23 was irregularly changed. NMR analysis demonstrated the moisture migrated through the extracellular spaces as free water under the action of osmotic pressure gradient during the salting treatment. Moisture and fat contents in caviar remained unchanged during the overall storage time. There was a trend for increased TVB‐N values over the 11 months storage. Color measurement was carried out to evaluate the quality change of the caviar. The NMR parameters clearly showed good correlation with moisture.
Caviar is one of the most expensive fishery products which not only contain protein, but also essential amino acids, trace elements, vitamins and high unsaturated fatty acids. The monitoring and analysis of the quality changes of caviar are essential during the period of caviar processing and storage. Herein, the low‐field nuclear magnetic resonance (LF‐NMR) and magnetic resonance imaging (MRI) methods were developed and tested to assess the proton changes of caviar during cryopreservation at −4°C for as long as 11 months. The use of LF‐NMR and MRI technique is fast, noninvasive, inexpensive, and visualization results are expected. This approach developed in this study is quite general and can be applied to monitor the proton changes of caviar storage in a noninvasive and fast way.