Preserving fish quality through intense pulsed light: microbial inactivation and ATP degradation control

In this study, six types of fish were treated with intense pulsed light (IPL) with a total energy fluences of 3.6-28.4 J/cm² and the maximum microbial inactivation levels of six fish were shown 1.23-1.85 log. Also, K ₁ value and hypoxanthine ratio, which are indicators of fish freshness and degradation, were measured to confirm the degree of decay by storage period according to the energy fluences of IPL. In all fish, IPL reduced the rate of hypoxanthine accumulation at specific timepoints depending on the energy fluence. For example, in red seabream treated at 17.1 J/cm², the hypoxanthine ratio on day 10 was reduced by 74.9% compared to the control. Meanwhile, irradiating excessively large energy fluences of IPL can rather promote deterioration of freshness in fish during storage period. Therefore, it is necessary to optimize the treatment conditions of IPL that minimize the acceleration of ATP degradation while maximize the microbial inactivation.