The influence of tumbling methods on quality, Myofibrillar protein oxidation, and microbial diversity in slightly acidic electrolyzed water-pretreated flounder (Paralichthys olivaceus) fillets during Superchilling storage

This study investigated the effects of static soaking (SS), atmospheric tumbling (AT), vacuum tumbling (VT), and ultrasonic-assisted vacuum tumbling (U-VT) on the quality of slightly acidic electrolyzed water-pretreated flounder fillets during superchilling storage (−1 °C). U-VT achieved the highest marinade absorption rate. However, VT demonstrated superior preservation efficacy, significantly inhibiting the growth of Pseudomonas and psychrophilic bacteria, and delaying the increase in total volatile basic nitrogen (TVB-N) and K-value. Conversely, U-VT accelerated myofibrillar protein oxidation, evidenced by the most pronounced decrease in total sulfhydryl content and increase in carbonyl content. Microbial diversity analysis indicated Pseudomonas and Clostridium became dominant during storage, with Pseudomonas weihenstephanensis identified as the specific spoilage organism. The findings reveal that while ultrasound enhances efficiency, it exacerbates oxidation and spoilage; VT optimally maintains quality by mitigating protein oxidation and modulating spoilage microbiota, providing a viable strategy for superior aquatic product preservation.