Effect of tea polyphenol–trehalose complex coating solutions on physiological stress and flesh quality of marine-cultured Turbot Scophthalmus maximus during waterless transport

Abstract

Objective: The waterless transport of live fish has changed the present situation of live-fish transport. However, the waterless transport environment may cause stress in fish. This research evaluated the effect of tea polyphenol–trehalose (TPT) coating solutions on Turbot Scophthalmus maximus during waterless transport. Methods: After cold acclimation, Turbot were coated and subsequently transported in a waterless environment for 18 h. Physiological and biochemical parameters were measured, including lysozyme (LZM) and immunoglobulin M (IgM) activities, serum creatinine (Cr) and uric acid (UA) concentrations, and nutritional flavor. Result: The results showed that the nonspecific immunity of Turbot was inhibited during the waterless transport; the LZM activity first increased and then decreased, and the serum Cr and UA concentrations significantly increased. In addition, the waterless transport promoted the breakdown of Turbot flesh proteins, leading to changes in nucleotides and free amino acids (FAAs). After waterless transport, the LZM and IgM activities in the TPT-treated Turbot were higher than those in the control group (CK), and the changes in FAA content and nucleotides were smaller than those observed in the CK group. Conclusion: This study shows that the use of TPT coating solution can reduce the impact of waterless transportation stress on the immune and metabolic functions of Turbot and can maintain the meat quality and flavor of Turbot.