Improving fermentation quality of Sichuan radish paocai through co-inoculation of homo- and heterofermentative lactic acid bacteria

This study investigates the effects of lactic acid bacteria, including Lactobacillus brevis (B), Lactiplantibacillus plantarum (P), and Lacticaseibacillus rhamnosus (R), on the fermentation and quality of Sichuan radish paocai (SRP) through both single and mixed inoculations. The mixed culture PRB (P + R + B) achieved rapid acidification and balanced homo-heterofermentative metabolism. It maintained high LAB viability and modulated yeast populations, potentially enhancing flavor complexity and microbial stability. PRB fermentation resulted in improved lightness, texture, and umami-related amino acids, and a volatile profile resembling that of naturally fermented SRP. Despite higher lactic acid levels, PRB yielded a harmonious flavor compared to the more sour B and PB groups, possibly due to a more balanced acid profile. Nitrite reduction (67%) was also observed. This study demonstrates that PRB co-inoculation optimizes SRP production by integrating efficient fermentation, enhanced sensory quality, and microbial safety providing a practical strategy for standardized, high-quality paocai manufacturing. • Co-inoculation of homo- and heterofermentative LAB enhanced paocai fermentation kinetics. • The microbial community structure influenced the accumulation of key flavor compounds. • Co-inoculation improved the balance of organic acids, volatile compounds, and texture. • Distinct metabolic pathways contributed to the flavor enhancement of Sichuan radish paocai.