Abstract: Objective: To examine the effect of a blend of rosemary extract (RE) and ε-polylysine (PL) on the quality and water migration of large yellow croaker (Pseudosciaena crocea) during ice storage. Methods: The fish were immersed in the blended solution (RP) containing 2 g of RE and 1 g of PL per 1 L for 20 min, and then each sample was taken out of the solution, packaged in a polyethylene bag and kept on ice at 4 ℃. Control samples were treated with sterile water. Sensory evaluation, physicochemical properties (pH, total volatile basic nitrogen (TVB-N) content, thiobarbituric acid reactive substances (TBARS) value, and electrical conductivity) and total viable count (TVC) were measured during storage. Water mobility was investigated by measurement of water-holding capacity (WHC) and low-field nuclear magnetic resonance (LF-NMR). Results: The control samples showed unacceptable sensory quality, with a dull color, loose texture and strong rancid smell on Day 9 of storage, whereas the RP treated samples maintained good sensory quality except for a slightly dull color on Day 13. pH and electrical conductivity descended firstly and then ascended during storage, and the values of the two parameters as well as TVB-N content, TBARS value and TVC in the RP group were lower than in the control group, suggesting that RP has great antioxidant and antibacterial activities. From the results of WHC and LF-NMR, it was apparent that RP could improve the WHC of large yellow croaker greatly, inhibit the increase in free water content and delay the deterioration process. The storage life of the control group was 6–9 days, and it was extended to 13–15 d by RP treatment. Conclusion: The composite preservative of RP can improve the storability and extend the shelf life of large yellow croaker without affecting its sensory quality.

Key words: rosemary extract blend, large yellow croaker, ice storage, quality change, water migration