The impact of desmin on texture and water-holding capacity of ice-stored grass carp (Ctenopharyngodon idella) fillet

The objective of this work was to analyse the role of desmin in texture softening and water-holding capacity (WHC) of ice-stored grass carp fillet. Results indicated that shear force of the fillet decreased sharply within 3 days, while drip loss increased during the whole ice storage. Water mobility and distribution were measured by low-field H-1 NMR T-2 relaxation that revealed a positive correlation (P < 0.01) between WHC and the mobility of the immobilised water (T-21 relaxation time). Meanwhile, negative correlation could be established between intact desmin and drip loss (P < 0.01). Intact desmin was extremely correlated with shear force (P < 0.01) and positively correlated with calpains activity (P < 0.05). This study demonstrated that the degradation of desmin was involved in the mobility of the myofibrillar water and softening of grass carp fillet during ice storage. Furthermore, calpains autolysis seemed to result in desmin degradation.