Proteomic insights into the mechanism of atmospheric cold plasma in reducing muscle protein degradation in Pacific white shrimp (Litopenaeus vannamei) during cold storage

This study investigated the effectiveness of atmospheric cold plasma (ACP) treatments at different voltages (10-50 kV) in mitigating muscle protein degradation and maintaining the quality of Pacific white shrimp (Litopenaeus vannamei) during refrigerated storage at 4 °C. Shrimp samples were treated with ACP at various voltages, and physicochemical indices, including trichloroacetic acid (TCA)-soluble peptides, acid-soluble nitrogen (ASN), and free amino acid (FAA) contents, were monitored throughout storage. Proteomic analysis was conducted to identify differentially expressed proteins (DAPs), followed by Gene Ontology (GO), KEGG pathway, and protein-protein interaction analyses to elucidate functional alterations. Findings indicated that the 50 kV ACP treatment markedly retarded the buildup of TCA-soluble peptides and ASN, and alleviated fluctuations in FAA levels relative to the control. Over the 0-12-day storage interval, fewer differentially abundant proteins (DAPs) were identified in the 50 kV-treated group than in the untreated control group. Bioinformatic analyses suggested that these DAPs were largely linked to the preservation of protein structure. Correlation analysis suggested that reactive species generated by ACP induced oxidative modification of key endogenous proteases (cathepsins B, L, D, and calpains), leading to conformational changes that inhibited enzyme activity. Consequently, hydrolysis of myosin heavy chains and actin was reduced, preserving myofibrillar integrity, protein solubility, and cytoskeletal stability. Overall, ACP treatment effectively impeded protein degradation through a non-thermal mechanism, offering a sustainable preservation strategy to extend the shelf life of shrimp and other high-protein aquatic products while minimizing quality deterioration and economic losses.