The inhibitory effect of water-tailored natural deep eutectic solvents (NADES) constructed from citric acid and trehalose with different amounts on the quality deterioration and oxidation of frozen-thawed (F-T) mirror carp ( Cyprinus carpio L. ) surimi was studied. NADES was obtained by citric acid to trehalose and the effect of moisture addition (v/v) on the structure, physicochemical, and anti-freezing capacity of NADES was assessed. NADES + 10 % H 2 O has relatively low viscosity (25 %) and strong freezing resistance. However, a 50 % H 2 O addition leads to the disappearance of the hydrogen bond. The addition of NADES effectively inhibits water loss, migration, and mechanical damage on F-T surimi. An inhibitory effect of 4 % (w/w) NADES on oxidation was verified by a decrease in carbonyl contents (17.4 %, 8.63 %) and TBARS (37.9 %, 15.2 %) of surimi compared with control ( P < 0.05) and sucrose + sorbitol after 5F-T cycles, suggesting the potential of NADES as a cryoprotectant for the food industry.
Nucleotide degradation in fish is an important biochemical change after death, which is closely related to freshness and sensory quality. However, except ATP-relative nucleotides, it remains unclear about changes in other nucleotide metabolites during postmortem stage. In this study, a strategy for the simultaneous quantification of 28 nucleobases, nucleosides, and nucleotides using hydrophilic interaction chromatography coupled with tandem mass spectrometry (HILIC-MS/MS) with positive/negative ion switching was developed. This method showed good linearity, precision, repeatability, and recovery. Furthermore, it was successfully applied to monitor the postmortem nucleotide degradation of turbot mince during chill (4 °C) and partial freezing (−3 °C) storage for 168 h. It was noted that the patterns of the changes in nucleotide metabolites differed considerably depending on the storage temperature. Meanwhile, the different pathway and speed of nucleotide catabolism in turbot mince was summarized based on the quantification data.
危险品化学品经营许可证（带存储）