Effects of compound anti-stress agents on biochemical characteristics, tissue metabolism and quality of spiny lobsters (Panulirus argus) during waterless preservation

The spiny lobster ( Panulirus argus ) is a commercially important species worldwide. Waterless live transport reduces costs and logistical complexity but induces severe hypoxic and dehydration stress, often resulting in high mortality and quality deterioration. However, the underlying metabolic regulatory mechanisms remain largely unclear. In this study, we investigated an integrated anti-stress strategy combining a two-step gradient cooling pretreatment with a composite formulation (vitamin C, glucose, taurine, and branched-chain amino acids). Lobsters were sampled at 0, 36, 48, and 60 h during simulated waterless transport. Physiological and biochemical assays, untargeted LC-MS/MS metabolomics, and systematic muscle quality evaluation were performed. After 60 h of simulated waterless transport, physiological and biochemical responses were significantly improved in the treatment group (FSY): malondialdehyde (MDA) levels were equivalent to 50.4% of those in the control group, while heat shock protein 70 (Hsp70) expression at 48 h was 63.4% higher, indicating markedly alleviated oxidative damage and strengthened cellular stress resistance. Metabolic reprogramming in the hepatopancreas was further revealed by temporal circular heatmap and untargeted metabolomics analyses, showing sequential adaptive changes: early activation of lipid metabolism and mTOR signaling for membrane stabilization and pre-adaptation; mid-phase enhancement of glutathione metabolism and autophagy for sustained antioxidant defense; and late-stage induction of the FoxO pathway to maintain long-term metabolic homeostasis and stress acclimation. Muscle quality and flavor were also effectively preserved: the FSY group showed a 7.4% increase in water-holding capacity, a 68.0% increase in inosinic acid (IMP), and lower total volatile basic nitrogen (TVB-N; 13.25 vs. 19.36 mg/100 g), confirming improved freshness and flavor stability. In conclusion, this integrated pretreatment systematically enhances antioxidant capacity, immune function, and sequential metabolic adaptability, providing a practical and theoretical foundation for efficient, high-quality waterless live transport of spiny lobsters in commercial aquaculture.