# TMT Quantitative Proteomics Reveals the Molecular Mechanism Behind Meat Quality Changes in Nile Tilapia Exposed to Environmental Concentrations of Microcystin-LR

## TL;DR

This study shows how microcystin-LR exposure affects the meat quality and protein levels in Nile tilapia.

## Contribution

The novel contribution is identifying proteomic changes and meat quality degradation in fish exposed to microcystin-LR at environmental concentrations.

## Key findings

- High-dose MC-LR exposure reduced meat quality by lowering pH and water-holding capacity and increasing oxidation.
- Proteomic analysis showed downregulation of ribosome-related proteins, indicating impaired muscle protein synthesis.
- Low MC-LR accumulation in muscle tissue suggests minimal health risk to consumers.

## Abstract

This study investigated the effects of chronic MC-LR exposure (0 μg/L [Control], 1 μg/L [M1], 3 μg/L [M3], 10 μg/L [M10], and 30 μg/L [M30]) on the muscle nutrient composition, meat quality, and muscle proteomic profile of Nile tilapia (Oreochromis niloticus). In the high-dose group (M30), MC-LR exposure compromised the muscle antioxidant status of Nile tilapia, resulting in reduced meat quality, as evidenced by decreased pH value and water-holding capacity, elevated lipid/protein oxidation, and altered texture parameters (shear force and fragmentation index). Proteomic analysis further revealed a downregulation of proteins associated with ribosomes, suggesting an impairment of muscle protein synthesis in the M30 group. Moreover, despite chronic exposure, only low levels of MC-LR accumulated in the muscle tissue, indicating a negligible health risk to consumers. Collectively, these findings offered valuable insights into the impact of environmental MC-LR contamination on fish muscle quality and nutritional value.