Effect of freeze-thaw cycles on texture of Haliotis discus hanai muscle

Abstract:

In order to explore the effect of temperature fluctuations on the texture of shellfish muscle, the commercial quick-frozen abalone was selected as the research object, and the texture, water-holding, field nuclear magnetic resonance and protein oxidation of 5 times of freeze-thaw cycles were determined. The results showed that the stiffness, elasticity, and chewiness of the muscles decreased significantly with the increase of freeze-thaw cycles, which decreased to 11.21%, 3.03%, and 10.04% of the original values respectively after 5 cycles. On the contrary, the shear force increased significantly. The water retention studies found that the thawing loss, and cooking loss of muscles increased significantly from 2.28%, 16.09% and 38.51% to 10.50%, 28.53% and 43.67%, respectively. LF-NMR showed that the bound water was hardly affected during the freeze-thaw cycles and the relaxation times T₂₂ and T₂₃ of the immobilized water and free water shifted significantly to the right, and the corresponding peak area ratio P₂₂ significantly increased and P₂₃ significantly decreased. Changes in protein structure and function have an adverse effect on muscle texture. It was found that hydrophobicity increased first and then decreased, and carbonyl content decreased significantly while active sulfhydryl content increased significantly during the freeze-thaw cycles. The study has shown that the freeze-thaw cycle can damage the muscle texture of abalone, causing poor texture and lowering the value of the commodity, eventually affecting consumer acceptability.