Effect of Different Thawing Methods on Quality Changes of Prepared Antarctic Krill Paste

In this study, the effects of different thawing methods (blast water thawing, air thawing, ultrasonic thawing, refrigerated thawing and hydrostatic thawing) on the quality of Antarctic krill paste were investigated by analyzing the water retention properties, textural properties, protein oxidation, and lipid oxidation. The results indicated that krill paste thawed more rapidly in air-blasted flowing water. Nevertheless, the rate of thawing and cooking loss increased, which resulted in noticeable precipitation of water, and alleviated water retention ability. In contrast to other thawing methods, krill paste thawed by refrigeration exhibited minimal protein oxidation, which was confirmed by the highest salt-soluble protein content (33.39 mg/g) and the lowest carbonyl content (2.71 nmol/mg) . The total volatile basic nitrogen values (TVB-N) of krill paste thawed by blast water thawing and refrigerated thawing were 11.36 mg/100 g and 13.58 mg/100 g, respectively, which were significantly lower (P<0.05) when compared to air thawing (16.57 mg/100 g) and hydrostatic thawing (15.40 mg/100 g). The analysis of the krill paste quality resulting from five thawing methods revealed that krill paste thawed by refrigeration exhibited the lowest thawing loss and cooking loss, the most desirable textural characteristics, and a significantly reduced thiobarbituric acid values (TBARS) in comparison to the other thawing methods, indicating a lower degree of fat oxidation. Therefore, refrigeration during the thawing process can mitigate the oxidation of proteins and lipids in Antarctic krill paste, increasing water retention ability and decreasing thawing loss, making it a favored method for thawing krill paste.