Abstract:

The quality change of Antarctic krill during the storage at 0 ℃ and 3 ℃ was evaluated by pH, meat productivity, soluble protein content and sensory evaluation. Meanwhile, the change in relative molecular mass of proteins from Antarctic krill was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Results indicated that pH in Antarctic krill exhibited a gradual increase during the period of storage for 24 h at 0 ℃ and 3 ℃, which were 8.21 ± 0.01 and 8.28 ±0.02, respectively. The meat productivity was decreased from (61.92 ± 2.50)% to (22.65 ± 6.81)% and (13.64 ± 2.72)%, respectively. Soluble protein content also exhibited a decrease and reduced to (19.0 ± 0.50) mg/(10 g wet weight) and (25.5 ±2.00) mg/(10 g wet weight), respectively. Totally 5 protein bands after 1-h storage at 0 ℃ and 3 ℃ was shown in the SDS-PAGE, which had molecular weights of 49.5, 32, 29, 26 kD and 13.2 kD, respectively. However, the protein with molecular weights of 29 kD exhibited the fastest degradation. The highest and lowest values of sensory evaluation were 9.5 ± 0.05, 9.4 ± 0.12, 1.3 ±0.10 and 1.0 ± 0.08, respectively. All of these investigations suggested that the quality of Antarctic krill could be quickly decreased due to its autolysis during storage at 0 ℃ and 3 ℃. Therefore, in order to achieve the best quality and edible properties of Antarctic krill, the optimal processing should be completed within 10 hours at 0 ℃ and 3 ℃ during storage.

Key words: Antarctic krill, autolysis, quality change