Effects of Different Treatments on the Quality Characteristics of Nemipterus virgatus Sausages during Refrigerated Storage

This study aimed to compare the effects of optimal medium-high pressure coupled with heat treatment (OPH), optimal ultra-high pressure treatment (OP) and traditional two-stage heat treatment (H) on the quality characteristics of Nemipterus virgatus sausages during a refrigerated storage period of 60 days. During storage, changes in freshness indexes such as total bacterial count, total volatile basic nitrogen (TVB-N) content, thiobarbituric acid (TBA) value, pH and conductivity were determined as well as gel properties such as gel strength, water-holding capacity, whiteness and textural properties. The results showed that the total bacterial count, TVB-N content, TBA, conductivity and cooking loss of sausages increased gradually with storage time, while the sensory score, water-holding capacity, whiteness, gel strength, and textural properties progressively decreased. The pH increased first and then decreased. On the 60th day of refrigeration, TVB-N content was 14.04% and 27.12% lower and TBA value was 11.76% and 23.73% lower in the OPH treatment group than in the H and OP treatment groups, respectively. Additionally, the gel strengths of the H, OPH, and OP treatment groups were 2 365.82, 3 229.36 and 1 905.53 g·cm, respectively, and their water-holding capacities were 71.25%, 74.03% and 68.86%, respectively. In summary, OPH treatment was able to better maintain the quality of fish sausages and slow down flavor changes during refrigerated storage.