Quality assessment of fish burgers from deep flounder (Pseudorhombus elevatus) and brushtooth lizardfish (Saurida undosquamis) during storage at -18ºC

 Microbiological, chemical and sensory changes of fish burgers prepared from deep flounder (Pseudorhombus elevatus) and brushtooth lizardfish (Saurida undosquamis) were determined during storage at -18ºC for 5 months. Microbiological counts were including total plate count (TPC), total coliform (TC), Staphylococcus aureus, Psychotropic and Escherichia coli decreased throughout the frozen storage . Reduction of microbial load in brushtooth lizardfish was higher than that in deep flounder, except for Staphylococcus aureus counts that was almost equal in both groups . There was a significant increase in pH value in both groups (P<0.05) in first and second months of storage only. Moisture content increased in both groups at the end of 5th month, with increase of moisture in deep flounder fish burgers being higher than that in brushtooth lizardfish burgers. TVB-N values in both groups increased significantly (P<0.05 and P<0.008 for deep flounder and brushtooth lizardfish burgers, respectively) at the end of the second month, however, there was a decrease or no significant change afterward. TBA value of deep flounder fish burgers had a significant decrease (P<0.05) as storage time continued, however, it increased significantly in brushtooth lizardfish burgers at the end of second month (P<0.006) following by a decrease at the end of storage period. Peroxide value (PV) in both groups increased significantly (P<0.05 and P<0.002 in deep flounder and brushtooth lizardfish burgers, respectively) during storage time but a significant decrease was observed at the end of third and fourth months (P<0.005 and P<0.001 in deep flounder and brushtooth lizardfish burgers, respectively). Sensory parameters (color, texture, taste and general acceptability) for two groups decreased significantly (P<0.003 for all parameters in 2 groups) during storage with deep flounder fish burgers receiving higher scores than brushtooth lizardfish burgers at the beginning and end of the storage period.