The aim of this study was to investigate the effect of sodium lactate (SL) on the gel quality of cold-stored L. vannamei and its underlying mechanism. Fresh L. vannamei were soaked in 1%, 2%, 3% SL solution (or pure water as the control, HO group) for 30 min, followed by 3 days' cold storage at 4 °C. The results showed that cold storage significantly deteriorated the gel quality, compared with the fresh shrimp (FS group), and the HO group exhibited a significant decrease in gel strength and an increase in cooking loss ( p < 0.05). In contrast, SL treatment alleviated these quality defects in a concentration-dependent manner, with the 3% SL group showing the most prominent improvement. Proteomic analysis identified 1572 proteins in total. Compared with the FS group, the HO group had 174 differentially abundant proteins (DAPs), mainly involving degradation of structural proteins (e.g., myosin heavy chain, profilin, tubulin beta-2 chain), downregulation of energy metabolism enzymes (e.g., pyruvate kinase, arginine kinase), reduction of antioxidant proteins (e.g., glutathione peroxidase, copper/zinc superoxide dismutase), and impairment of immune-related proteins (e.g., prophenoloxidase-1, C-type lectin 2, penaeidin-3a). When compared with the HO group, the 3% SL group had 83 DAPs (65 upregulated, 18 downregulated), including significant upregulation of the aforementioned structural, energy metabolism, antioxidant, and immune-related proteins. The measurements of thiobarbituric acid reactive substances and protein carbonyl confirmed that SL significantly reduced oxidative damage in the 3% SL group compared with the HO group. Take together, SL attenuated protein degradation, protected energy metabolism homeostasis, and alleviated oxidative stress, thus improving the gel quality of cold-stored L. vannamei . • Cold storage impaired gel quality of L. vannamei. • Sodium lactate improved the gel quality of cold-stored L. vannamei. • Sodium lactate reduced structural proteins degradation of cold-stored L. vannamei. • Sodium lactate maintained energy and immune homeostasis of L. vannamei during cold storage.
Yin et al. (Wed,) studied this question.