Survey the effects of live Rainbow Trout handling on fish meat quality

Abstract

This research was performed to survey the live handling condition of Rainbow trout in Tehran province and determine the effects of this method on the quality of the flesh regarding with water binding capacity, pH changes, moisture, fat and protein content in different seasons of year. Based on reviews of Questionnaires, there were 20 main live rainbow trout sale centers in Tehran. 10 numbers of these were in fruit and vegetable centers of municipality and others were out of these centers. Live fish handling to in these areas mainly was performed from fish farms located in the Haraz road (85 percent), farms of Firoozkooh road (10 percent) and others were (5 percent) from neighboring provinces. The results of this study indicated that current methods of live handling in Tehran (the transporting time 4 h and the density of fish in tank 100-150 kg /m2) meat quality of transported trout was not affected. Water holding capacity of transported fish was less than caught fish in the fields. This amount was reached to lowest level in in summer as well as the differences between the two groups were significant (P<0.05). Also, when a meat pH level was elevated, water holding capacity was reduced. In summer, the amount of WHC in transported fish was 13.4% that was a highest value between the seasons. Appears that in the summer, high temperature and increasing kinds of stresses to fish during handling due to excessive accumulation of metabolites such as ammonia, muscle energy sources emptied because of high activity. In this condition, falling of pH during postmortem changes being moderated and lead to increase drip loss in the transported sample.