FISHERIES RESEARCH INSTITUTE,MOA,TAIWAN

Frozen Pacific saury (Cololabis saira) were thawed, brined, and smoked. Raw fish were pretreated with three treatments including round (gilled), semi-dressed, and semi-dressed and split from the back. The samples were soaked in 5%, 10%, or 15% brine for 2 d at 5 °C. The NaCl content of the flesh significantly increased on the first day, and thereafter continued to slowly increase. During the brining process, the pH value of the flesh remained unchanged; however volatile basic nitrogen (VBN) decreased, and the 2-thiobarbituric acid (TBA) value increased. This shows that there was little change in the aerobic plate counts (APCs), psychrophilic plate counts (PPCs), coliforms, and Escherichia coli during brining.The semi-dressed fish were immersed in 10% brine at 5 °C for 1 d, and then smoked. The smoking process included two methods: steam smoking (100% RH) at 65 °C for 15 min followed by smoking at 72 °C and 40% RH for 15~45 min (HHS); and smoking at 65 °C and 40% RH for 15 min followed by smoking at 72 °C and 40% RH for 15~45 min (LHS). During the smoking process, the moisture contents of both samples decreased, while the pH and VBN remained almost constant, and the TBA value increased. The L* value of the ventral skin of smoked Pacific saury decreased, while the a* and b* values increased. The appearance turned yellowish-brown after smoking. The toughness and cohesiveness of the flesh of smoked Pacific saury increased. Neither APC, PPC, coliforms, nor E. coli were detected. With the exception of the appearance, the flavor, texture, and acceptability of both products did not significantly differ (p > 0.05) according to the results of a sensory evaluation. These results show that the suitable smoking conditions for smoked Pacific saury are smoking at 65 °C and 40% RH for 15 min followed by smoking at 72 °C and 40% RH for 30 min.