Influence of short-term starvation on the muscle quality of commercial-sized grass carp ( Ctenopharyngodon idella)

The effects of short-term starvation on muscle common nutrition component and texture index of grass carp ( Ctenopharyngodon idella) were studied, in order to provide theoretical basis and reference data for improvement of the quality of grass carp in production practice. Ten common grass carp that reached the listing specifications and ten grass carp that starvation for 15 days were selected respectively in this research.The normal nutrition component, physic-chemical parameters, composition of fatty acid, muscle fibers diameter and the main texture index of grass carp muscle were determined. And according to the effect of short-term starvation on muscle common nutritional values, physic-chemical parameters and the main texture index, whether need to extend the time for starvation to 50 d was decided eventually.The results showed that there were no significant changes in water content, crude protein and crude fat content in grass carp after short-term ( 15 days) starvation, but the hardness, adhesiveness and chewiness decreased significantly, ash content, p H and conductivity increased significantly.In addition, short-term starvation significantly increased the content of PUFA ( carbon twenty alkyl acid) in grass carp muscle.After short-term starvation the characteristic tasty amino acids ( glutamic acid and asparagines) increased, and the characteristic sweet amino acids ( alanine and glycin) decreased. The data starvation for 50 days showed that the water content and crude fat content of the grass carp decreased significantly in comparison with the control group and the hardness, chewiness and adhesiveness of the grass carp were significantly higher than those of the group starvation for 15 days, but the hardness and adhesiveness were still significantly lower than the control group, there was no significant difference of chewing, the ash contentwas significantly higher than the control group.Therefore, the effects of starvation for 50 days are better than shot-term starvation ( 15 d) , when reduction of muscle fat content was one of the goals of starvation and the muscle fat content and the normal texture index of hardness, gumminess and chewiness were both considered.