Microbial and Sensory Characteristics of Traditional Watery Kimchi (Dongchimi) Fortified with Probiotics

Dongchimi, a traditional Korean watery kimchi, relies on complex interactions among diverse lactic acid bacteria (LAB) to maintain its freshness and quality. Recently, dongchimi has gained attention as a health-promoting food due to its content of probiotics and prebiotics. In this study, six probiotic strains were employed into dongchimi fermentation, and its sensory and microbial characteristics were evaluated. The LAB-enriched dongchimi demonstrated improved sensory preference (63%) and significantly higher LAB counts (average 5.2 × 10⁷ CFU/ml) compared to traditional dongchimi. Furthermore, microbial diversity between the LAB-enriched and traditional dongchimi was analyzed during the fermentation process using both culture-dependent Sanger sequencing and culture-independent metabarcoding techniques, employing 16S ribosomal RNA gene sequences. Lactiplantibacillus plantarum was identified as the dominant probiotic strain in both types of dongchimi, while other probiotics, including Bifidobacterium bifidum, B. animalis, Limosilactobacillus fermentum, and Heyndrickxia coagulans, were exclusively detected in the LAB-enriched dongchimi. In conclusion, Lactiplanti. plantarum and Limosi. fermentum were identified as the most effective probiotics for dongchimi fermentation. These results offer critical insights into the microbial ecology and probiotic strains essential for optimizing synbiotic dongchimi, thereby reinforcing health claims related to probiotics and prebiotics.