Hydrogen-incorporated reducing atmosphere packaging: effects on protein degradation and microbial diversity of Litopenaeus vannamei.

Modified atmosphere packaging (MAP) is a widely used technique for preserving aquatic products, but research on the application of hydrogen (H2) in seafood preservation remains limited. This study evaluated the effects of two MAP (MAP1: 50% carbon dioxide (CO2)/50% N2; MAP2: 75% CO2 /25% N2) and two H2- reducing atmosphere packaging (RAP, H2-RAP1: 0.5% H2 /50% CO2 /49.5% N2; H2-RAP2: 0.5% H2 /75% CO2 /24.5% N2) on protein degradation and microbial communities in Litopenaeus vannamei stored 4 °C. Protein degradation was assessed by trichloroacetic acid (TCA)-soluble peptides, myofibrillar protein (MP), free amino acids (FAA), and biogenic amines (BA), while microbial dynamics were analyzed using total viable count (TVC) and 16S rRNA high-throughput sequencing. Results showed that the H2-RAP2 group exhibited the best preservation effect. After 12 d, MP content in the H2-RAP2 group remained at 63.23 mg/g, significantly higher than in the other groups. The H2-RAP2 group also effectively delayed the accumulation of TCA-soluble peptides, FAA, and BA (mainly histamine, putrescine, tyramine, and cadaverine), while markedly suppressing TVC growth (5.91 log CFU/g). This study confirms the synergistic preservation effect of H2 and CO2, supporting the application of H2-RAP preservation of Litopenaeus vannamei and other aquatic products.