It is well known that immune defenses of bivalves against environmental and pathogenic stresses are primarily attributable to hemocytes. Hemocyte parameters are being used progressively as indicators to assess the host immune status. Moreover, there is increasing evidence that seasonal variations on the immune status have two origins: exogenous and endogenous. In this work, we investigated the effects of seasonal exogenous (water temperature and food availability) and endogenous (size and reproduction) factors on the hemocyte parameters in the scallop Chlamys farreri. Scallops were monthly collected from February to December 2009 at 2 sampling sites differing in culture mode: Qingdao for monoculture and Weihai for scallop—kelp polyculture. Six hemocyte parameters including total hemocyte count (THC), granulocyte percentage (GP), intrahemocytic phenoloxidase (PO), acid phosphatase (ACP), superoxide dismutase (SOD), and peroxidase (POD) were analyzed. Results illustrated that all hemocyte parameters exhibited marked seasonal variations, following a similar pattern at both sites. High values of THC, GP, PO, and POD were observed in spring and early summer, a period of favorable water temperature and high food availability and gonad index, whereas low values were found in summer and early autumn, a period corresponding to reproduction completion and high water temperature. Moreover, SOD was lowest in February and highest in August, and correlated positively with water temperature. Hemocyte parameters in the scallop C. farreri varied greatly among seasons, and their values were generally low during summer and early autumn, suggesting that scallops had a depressed immune status during this period.

In this study, the effect of high‐intensity ultrasound (HIUS) (200 and 400 W for 0, 5, 10 and 15 min respectively) on conformational changes, physicochemical, rheological and emulsifying properties of scallop (Patinopecten yessoensis) myofibrillar protein (SMP) was investigated. HIUS‐treated SMP had lower α‐helix content and higher β‐sheet content compared with the native SMP. HIUS treatment induced the unfolding of SMP and increased the surface hydrophobicity. The particle size of SMP decreased and the absolute zeta‐potential increased after ultrasonication, which in turn increased the solubility of SMP. The conformational changes and the improvement of physicochemical properties of SMP increased the ability for SMP to lower the interfacial tension at the oil–water interface and increased the percentage of adsorbed protein. As a result, the emulsifying properties, rheological properties of SMP and storage stability of emulsions were also improved. In conclusion, HIUS treatment has future potential for improving the emulsifying properties of SMP.