Mitigating Effect of Ginger Extract on Survival Rate and Muscle Quality of Crucian Carp (Carassius auratus) Under Transportation Stress

This study evaluated the effects of ginger extract, applied via four methods-direct addition, microencapsulation, and combinations with NaCl or eugenol-on stress responses and muscle quality in crucian carp during transportation. Among the treatments, microcapsules and the eugenol compound showed the best results, each achieving a 50% survival rate after 72 h. The microcapsule group provided prolonged antioxidant protection, stabilized water quality, reduced cortisol levels, suppressed pro-apoptotic gene expression (<i>hsp70</i>, <i>hsp90</i>, <i>il-6</i>, <i>caspase 3</i>, <i>caspase 8</i>, and <i>bax</i>), while upregulating the anti-apoptotic gene <i>bcl-2</i>. These alterations contributed to lower lactic acid accumulation and glycogen consumption, enhanced muscle shear force, reduced drip loss, and improved structural integrity of the gill, liver, and muscle tissues. The eugenol group effectively limited ammonia nitrogen accumulation, decreased glutathione peroxidase activity, and downregulated stress and apoptosis-related genes (<i>bax, caspase 3</i>, and <i>caspase 9</i>), resulting in reduced tissue damage. In contrast, the NaCl compound group accelerated water quality deterioration, increased TDS (total dissolved solids), lowered dissolved oxygen, and weakened stress resistance, leading to more severe tissue damage. Overall, microencapsulation or eugenol co-application were the most effective strategies for enhancing survival and maintaining muscle quality during transportation.