Inhibitory Effects of Modified Atmosphere Packaging Using Pure Oxygen on Discoloration of the Dark Muscle in Cultured Yellowtail (Seriola quinqueradiata) During Refrigerated Storage

ABSTRACT This study showed that the dark muscle of yellowtail stored in pure O2 had almost unchanged redness, pH, and MetMb formation during 72-hour storage, while the N2 and air groups had significantly lower redness and pH, and significantly higher MetMb formation indices. Lactic acid content showed a significant negative correlation with pH. Pearson correlation analysis demonstrated that the lower redness was correlated with the lower pH and higher MetMb formation index. Thus, pure O2 could inhibit the MetMb accumulation and decrease pH, thereby suppressing discoloration and making the dark muscle more likely to gain bright red color.