Seafood is highly perishable, and its spoilage begins immediately after harvesting due to the production of various metabolites. However, freezing, a conventional long-term preservation technology, causes quality degradation due to ice crystallization. Supercooling has emerged as a promising technique to prevent ice formation and quality degradation. In this study, tuna fillets were supercooled at -3.5 degrees C with an external pulsed electric field (PEF) and oscillating magnetic field (OMF) strengths for optimization. Quality factors such as drip loss, color, microbial analysis, texture, and total volatile basic nitrogen (TVB-N) were evaluated in comparison with refrigerated, frozen -thawed, and supercooled samples stored for 1, 4, 7, and 10 days. The results showed that supercooled samples had lower TVB-N values than refrigerated samples. The aerobic plate counts of supercooled tuna samples did not significantly vary from 1 to 7 days of storage. Moreover, supercooling preserved the textural integrity of the product and reduced drip loss compared to frozen -thawed samples. Therefore, supercooling preservation can extend the shelf -life of tuna fillets while minimizing quality degradation, indicating its potential compared to conventional refrigeration and freezing methods.