Preservation of bighead carp heads using black pepper essential oil: biogenic amine inhibition and metabolomic insights

This study evaluated the efficacy of black pepper essential oil (BPEO) as a natural preservative for bighead carp heads during superchilling storage, with a focus on controlling biogenic amine (BA)-producing bacteria. Six dominant BA-producing strains were isolated and identified. BPEO exhibited measurable in vitro growth-inhibitory effects and reduced detectable amino acid decarboxylase protein levels in certain strains. Compared with controls, BPEO treatment delayed sensory deterioration, reduced total viable counts in fish meat by approximately 1.0 log CFU/g, lowered TVB-N values by about 24% at day 8, and extended shelf life by approximately 2 days. Untargeted metabolomic analysis indicated that BPEO treatment was associated with alterations in BA-related metabolic pathways. Notably, putrescine (PUT) levels at day 10 were significantly lower in the BPEO-treated groups compared with controls (p < 0.001). Reduced PUT accumulation was accompanied by changes in ornithine- and proline-related metabolites in fish meat. This study provides integrated microbiological and metabolomic evidence supporting BPEO as a plant-derived preservation strategy to enhance the safety and quality of aquatic products.