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 (H 2 ) in seafood preservation remains limited. This study evaluated the effects of two MAP (MAP1: 50% carbon dioxide (CO 2 )/50% N 2 ; MAP2: 75% CO 2 /25% N 2 ) and two H 2 - reducing atmosphere packaging (RAP, H 2 -RAP1: 0.5% H 2 /50% CO 2 /49.5% N 2 ; H 2 -RAP2: 0.5% H 2 /75% CO 2 /24.5% N 2 ) 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 H 2 -RAP2 group exhibited the best preservation effect. After 12 d, MP content in the H 2 -RAP2 group remained at 63.23 mg/g, significantly higher than in the other groups. The H 2 -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 H 2 and CO 2 , supporting the application of H 2 -RAP preservation of Litopenaeus vannamei and other aquatic products.