Impact of ultrasound combined with slightly acidic electrolyzed water treatment on quality characteristics and microbial inhibition of Tan mutton

This study evaluated ultrasound combined with slightly acidic electrolyzed water (SAEW) treatment (0-5 min) on microbial safety, physicochemical properties, protein structure, and flavor of Tan mutton. The 1-min treatment achieved optimal balance, reducing total viable counts (TVCs) from 5.85 to 5.13 log CFU/g and Pseudomonas from 4.61 to 4.49 log CFU/g compared with control. Physicochemical improvements included decreased cooking loss (39.77% to 34.47%), substantial hardness reduction (7730.15 g to 2993.64 g), no significant change in centrifugal loss, and 16.05% elasticity increase. Color attributes improved markedly ( L* increased from 34.56 to 41.78; a* decreased from 9.67 to 6.10). FTIR analysis revealed protein structural transitions: α-helix decreased from 41.23% to 31.42%, while β -sheet (19.37%-25.13%) and random coil structures (16.51%-22.94%) increased, indicating moderate myofibrillar unfolding. SEM confirmed that 1-min treatment preserved compact microstructure, whereas 3-5 min treatments resulted in noticeable fiber disruption. GC-MS and electronic-nose analyses demonstrated enhanced nutty/roasted volatiles (e.g., 1-pentanol, 2-pentyl-furan) while suppressing off-odor aldehydes such as hexanal and ( E )-2-nonenal. Correlation analysis revealed close relationships among protein structural changes, microbial inhibition, water-holding capacity, and aroma development. The 1-min ultrasound-SAEW combination achieved the optimal balance between microbial reduction and quality enhancement, offering a promising green preservation strategy for high-quality Tan mutton products. • This study explored the sterilization efficacy and quality of Tan mutton treated with ultrasound and SAEW. • Optimal sterilization achieved at 1-min treatment, reducing total viable counts and Pseudomonas counts. • 1-min treatment enhanced meat tenderness increases elasticity, and imparts a fresh, fruity aroma. • Moderate treatment (1-2 min) decreased α -helix content while increasing β -sheet and random coil structures. • Quality and flavor enhanced via improved water retention, brightness, and aroma.