Micro-nano bubble-assisted fasting improves the meat quality of Pelodiscus sinensis by modulating gut microbiota and metabolic profiles.

This study investigated the effects of micro-nano bubble (MNB)-assisted fasting on the meat quality of Chinese soft-shelled turtle (Pelodiscus sinensis). Compared to conventional fasting, MNB treatment significantly improved muscle elasticity and enhanced umami intensity by retaining higher levels of glutamic and aspartic acids. GC-IMS and electronic nose analyses confirmed that MNBs effectively reduced off-flavors (e.g., dimethyl sulfide, hexanal) while preserving polyunsaturated fatty acids (EPA, DHA). Integrated metabolomics and microbiome analyses revealed that MNBs remodeled the gut microbiota-enriching beneficial Romboutsia and suppressing spoilage-associated Aeromonas. This microbial shift, alongside the oxidative modulation of the aquatic environment, curbed the generation of sulfur-containing off-flavors and preserved lipid nutrients. Consequently, MNB-assisted fasting emerges as a valuable ecological strategy to enhance the sensory and nutritional quality of cultured turtles.