Reduction of histamine levels in tuna fish with micro nano bubble ozone venturi system treatment

Histamine content is a key indicator of marine fish safety. Histamine levels above 15 ppm may trigger allergic reactions, while concentrations exceeding 100 ppm can cause poisoning. This study aimed to reduce histamine levels in tuna using the Micro Nano Bubble Ozone (MNBO) venturi system. The research employed three treatments: untreated tuna (control) and washed tuna with MNBO for 15, 30, 45, and 60 minutes. Tuna samples weighed an average of 250 g. The MNBO system consisted of a 20 g/h ozone generator, a 900 L ozonized water tank equipped with a 150 W submersible pump, and a ¾- inch venturi injector, connected to a 1.0 × 1.5 × 0.7 m washing tank. During washing, dissolved ozone concentrations range from 0.09 to 0.19 ppm. Histamine was analyzed using a spectrofluorometric method following SNI 2354.10:2016. The 45-minute MNBO treatment produced the most significant reduction, achieving a decrease of 1.76 log cycles. These findings demonstrate that MNBO technology is effective in lowering histamine levels in tuna and has potential applications in enhancing seafood safety during post-harvest handling.