Effect of ultra-high pressure on gel properties of fish (Nemipterus virgatus) sausage

Changes of the gel strength, springness and chromatic value of fish (Nemipterus virgatus) sausage at different pressure and time were analyzed at 25℃, and the effect of ultra-high pressure (UHP) on them also was investigated. The results showed that the gel strength increased slightly with increasing pressure below 15min. When the processing time was 15min or 20min, the gel strength increased firstly and then decreased with increasing pressure and reached a maximum value at 300MPa. The springness increased firstly and then decreased with increasing pressure and time, and reached a maximum value at 400MPa when the time at 15min. L* and whiteness increased significantly with increasing pressure and dwell time, but increased slowly in 400⁵00MPa, on the contrary, both a* and b* reduced gradually. Dyeing observation of hematoxylin-eosin (HE) staining showed that porosity of network structure of the gel declined with increasing pressure and its roundness increased. Uniformity and compactness of network structure reached the highest value in 300MPa. When the pressure continued to increase, the pore of network structure increased even ruptured.