Effects Of Slaughter Method And Blood Deposition On Fish Quality

Trachurus japonicus and Seriola quinqueradiata as the important economic consumption, as people to fish the fresh degree of the intermediate products demand is higher and higher, producers and circulation are listed to fish catch and the fish died in the process of change delay study, this study mainly aims at the execution method of live fish in different conditions and to take off the blood and blood sedimentation effect with chemical and physical methods to further explore the change of after the death of fish freshness, the specific research results are as follows:1. Under 0℃ iced condition,using two different methods that spinal cord with blood removal and Hypoxia without blood removal to lethal Japanese horse mackerel. pH of Spinal cord damage group is lower than hypoxic lethal witheout blood off group.pH of two groups are tended to decrease with storage time. Both initial pH lower than kill time. Hypoxia lethal blood group initial pH value is not off far below the spinal cord damage blood removal group. Spinal cord damage blood removal set a * value higher than hypoxic death without the blood off group, b *, L * value of less than lethal hypoxia without the blood off group.after 144 h, two group of k values are less than 20%.0℃ ice storage conditions,two groups could maintain a good indicator of freshness.2. Under 10℃ water condition,using three different methods that spinal cord with blood removal 、spinal cord without blood removal and Hypoxia without blood removal to lethal Japanese horse mackerel. the average p H of the killing: spinal cord with blood removal group> spinal cord without blood removal group> hypoxia death without blood removal group. Three groups of pH at 10 ℃water storage tended to decrease within 48 h, After 48 h, pH values are on the rise. But the initial pH is higher than that killed time. the initial pH value of hypoxia group is higher than other two groups. the value of a *, b * of Hypoxia death is greater than the other two groups, L * value of spinal cord damage blood removal group is highest.the spinal cord within 48 h blood removal group of k values greater than 20%,other two groups are remaining under 20%. after 96 h storage, three groups of freshness are more than 20%, freshness value dropped significantly. after 48 h, spinal cord damage method can not explain the lethal method is the best method to kill fish.3.Under 10℃ water condition,using two different methods that spinal cord with blood removal and Hypoxia without blood removal to lethal Japanese horse mackerel. Divided into upper and lower sides were placed,pH in 10 ℃water storage tended to decrease during 96 h, pH values of Place position that the upper side were higher than the lower side, Hypoxia without blood removal group initial pH value lower than the spinal cord damage group with blood removal. a * value of hypoxia group is greater than the spinal cord with blood removal group, upper side of the a * values were higher than lower side, k value of 96 hours storage, Hypoxia death without blood removal of lower side> hypoxic death without blood removal of upper side> spinal cord damage with blood removal of lower side> spinal cord damage with blood removal of upper side. Freshness that the spinal cord group is greater than hypoxia group,placed of upper side is higher than lower side. enzyme activity that hypoxia group is greater than the spinal cord group, Thus, the results showed that the quality of meat is placed the upper side is greater than placed the lower side, the spinal cord is the best group.