The Effect Of Salinity Change On The Quality Of Gift Muscle

The effect of salinity changes on muscle quality of GIFT (Oreochromis niloticus) wasstudied to search for a feasible measure of improving tilapia muscle quality.physical-chemical indexes such as nutrition content (basic nutrition composition, amino acid,fatty acid), water binding capacity, pH, cooking loss rate and sensory indexes such asflavouring material (inorganic ion, nucleotide, free amino acid), fleshcolor, shear force,texture, sensory evaluation of tilapias from fresh water were determined when the salinity ofwater reached18and36，respectively. The results showed that after the treatment, themoisture content of the muscle of tilapias decreased and the contents of fat, protein, ash,amino acids and fatty acids in the muscle increased.what’s more, the nutritional value oftilapia’s muscle was much higher; While the content of free amino acids and inorganic ions(Na+, K+, Cl-) of muscle and the content of inosine monophosphate (IMP) in the muscle oflarge-sized tilapias also increased when the salinity of water has been increased.Then theflavour of muscle was enhanced, especially the umami and sweetness of the meat; Because ofthe nutrients changes in the muscle and the stress responses of tilapias after the salinity ofwater changed, the mechanical strength (hardness and chewiness) of the muscle wasenhanced, and the tenderness of muscle was decreased; The brightness of the muscle also wasimproved.Thus, the taste and appearance of tilapia’s muscle changed.Consequently, in the early post-processed after completing the adjustment of watersalinity, the quality of tilapia was higher. In the later stage due to the impact of hunger, energyconsumption in the osmoregulation, the drop of immunity and other physiological functions,the nutritional value and the quality of appearance declined.