ROLES OF APOPTOSIS AND AUTOPHAGY ON THE TEXTURE OF RED SEA BREAM MUSCLE

One of commercial brands in farmed-products of red sea bream (Pagrus major), named "Date-Madai", is known to possess hard texture and transparency when served as "Sashimi". The quality of "Sashimi" is usually evaluated by texture, appearance, and color of dark muscle. These characters easily change worse during post mortem storage. The aim of this study was to reveal relationship between proteolytic degradation and muscle quality of the red sea bream. Sensory analysis was carried out to evaluate the quality of "Sashimi" in terms of texture and appearance of flesh. Western blot analysis was conducted to evaluate protein expressions of red sea bream muscle. Significantly higher score in the sensory analysis for brightness was given to the "Date-Madai". Similar tendency were also observed in color, texture and general acceptability. Intracellular effector of the apoptotic pathway includes contributin of caspase family. Lower level in caspase-3 protein was observed in the "Date-Madai" muscle. Autophagy is known to be inhibited by the target of rapamycin (TOR) signaling. Phosphorylated ribosomal protein S6 kinase, which is in the downstream of the TOR, increased in the "Date-Madai" muscle. This study concluded that the apoptosis and autophagy could be associated with the quality of the red sea bream.