The influence of waiting period before freezing on the sensory quality deterioration of fish meat caused by freezing.

In this study, the effect of different waiting period (0 h, 12 h, 24 h, 48 h) between the killing and the freezing of the horse mackerels (Trachurus japonicus) was investigated. Samples were stored at 4°C. Two experiments were carried out. One is sensory evaluation, other is the measurement of maximum force. In sensory evaluation, we compared the samples that frozen just after the killing (0 h) and that frozen after 2 days after killing (48 h). As a result, we found almost no difference in the sensory factors such as taste and smell. But we confirmed significant difference in firmness which was showed to be higher in the sample frozen after 0 h than that frozen after 48 h. Therefore, we measured maximum force in indentation tests of horse mackerel. We presumed maximum force decrease with elongating postmortem time, but we had not seen such changes. However, stress-strain curves showed different trend. Thus, it was found the texture of fish meat could not be evaluated by measurement of maximum force in this study.