Effects of adding various salted seafood (jeotgal) types on the microbial, metabolic, and sensory dynamics of kimchi during fermentation

Kimchi is a traditional Korean fermented dish in which salted seafood is widely used; however, its specific role in fermentation remains unclear. This study investigated the impact of four salted seafoods (anchovy, cutlass offal, yellow croaker, shrimp) on the physicochemical, microbial, metabolic, and sensory properties of kimchi compared to a no-seafood control. Samples were fermented at 4 °C for 6 weeks. Salted seafood accelerated acidification and increased total and amino nitrogen, hypoxanthine, inosine, and free amino acids (e.g., glutamic acid, γ-aminobutyric acid). Halophilic lactic acid bacteria, including Tetragenococcus halophilus , were enriched in anchovy kimchi at early stages, whereas latilactobacillus sakei dominated all samples at mid–late fermentation. Metabolomic profiling and electronic tongue analysis revealed enhanced accumulation of flavor-related metabolites and stronger umami and sourness in seafood-supplemented kimchi, associated with organic acids and microbial succession. Overall, salted seafood functions as both a flavor enhancer and natural microbial starter in kimchi fermentation. • Salted seafood accelerated fermentation and increased amino nitrogen in kimchi. • Microbial succession varied by seafood type, stabilizing kimchi fermentation. • Salted seafood served as a microbial starter influencing fermentation. • Sensory changes were associated with microbial shifts in seafood-supplemented kimchi. • Bioactive and flavor compounds increased in salted seafood-supplemented kimchi.