Effect of Frozen Storage Temperature on Quality-Related Changes in Rainbow Trout (Oncorhynchus mykiss)

The effect of frozen storage temperature on quality-related parameters of rainbow trout (Oncorhynchus mykiss) muscle was studied in the interval from -10 to -80 degrees C on samples stored for 1 to 18 months. The following quantities were measured: drip loss, water holding capacity and water distribution, color, lipid oxidation (thiobarbituric acid-reactive substances, TBARS), and membrane stability (enzyme activity). No effect of temperature on drip loss, water holding capacity, water distribution, or membrane stability was observed for samples stored below -20 degrees C, whereas storage at -40 degrees C or lower compared to -30 degrees C or higher resulted in a reduced level of secondary lipid oxidation (TBARS). No advantage was gained by using temperatures below -40 degrees C for frozen storage of trout regarding any of the properties investigated.