Effects of oxygen environment and critical temperature regulation on waterless live-keeping technology of Litopenaeus vannamei

Aiming at the problems of great difficulty in live preservation, low survival rate and easy quality deterioration during the live transportation of Litopenaeus vannamei, we constructed an eco-critical temperature waterless live-preservation technology system based on precise oxygen regulation. We systematically investigated the regulatory mechanism of oxygenation coupled with low-temperature stress on shrimp survival and quality variation. Through single-factor experiments, we determined the optimal live-preservation parameters as follows: temperature 8 ℃, oxygen concentration 60%, and cooling rate 4 ℃·h^-1. Under these conditions, the 10 h survival rate of L. vannamei reached (90.2±5)%. We found that this technology can effectively activate the antioxidant enzyme systems (Such as POD and GSH-Px) in shrimp muscle, maintain stable activity of total superoxide dismutase (T-SOD), and significantly inhibit the accumulation of lipid oxidation products at the early stage of preservation. Flavor analysis reveals that the relative content of aldehyde fishy substances decreased from 22.66% to 14.82%, while the proportion of ketone compounds increased, thus optimizing the flavor profile. The technology significantly improved the texture properties of shrimp muscle; the tissue structure remained basically intact with only slight subcellular damage observed. Multidimensional correlation analysis demonstrates that texture stability was significantly positively correlated with antioxidant capacity, and negatively correlated with oxidation products and volatile aldehydes. This study clarifies the key role of oxygenation during waterless live preservation of shrimp, provides technical support for commercial live transportation and storage, and deepens the understanding of low-temperature stress mechanisms in crustaceans.