Mechanism of ammonia nitrogen on the muscle quality of Wuchang bream
(Megalobrama amblycephala) during transportation: effects of exposure
Changes on the muscle quality of Wuchang bream exposed to different
ammonia nitrogen (AN) models during transportation were investigated.
Upon AN stressing, fish gill apparently injured, resulting in the
increases of ROS content, apoptosis rate, and adjacent gap of muscle
cells, and the blurring of muscle fibers. These bio-physiologic changes
depended on AN exposure model, e.g., concentration and time. Among
different models, the fish exposed to high concentration AN (50 mg/ L)
showed the highest drip loss and lowest shear force under short time (3
h) and long time (24 h), respectively. Lightness of the fish exposed to
low concentration AN for long time was the highest, and the lowest
yellowness for the one exposed to fluctuate concentration AN for long
time. The mechanism on changes of muscle quality by AN exposure was
mainly related to the upregulation of MAPK/p53, NF-κB and PI3K/AKT
signaling pathways to modulate apoptosis.