Comparison of Browning Colour Formation on the Surface of Fish Samples during Grilling

Abstract

A comparison of the browning of fish species grilled using far-infrared (FIR) heating was evaluated. Japanese amberjack (Seriola quinqueradiata), Japanese Spanish mackerel (Scomberomorus niphonius), salmon (Oncorhynchus masou), and red sea bream (Pagrus major) were used. Temperature and colour (CIE L*, a*, and b* values) of the sample surface were monitored over time. The rate of L* change was evaluated by treating the browning reaction as a first-order reaction. Colour changes based on a* and b* values were correlated with L* values using empirical equations. During browning, the trajectories of sample colour changes followed almost the same pattern, except for salmon, which was probably due to astaxanthin content. Samples with higher fat content browned faster, according to their higher frequency factor (k₀) of the browning rate. An empirical equation for k₀ prediction based on sample fat content was obtained, giving fairly good approximations to measured values.