Color changes in fish during grilling – Influences of heat transfer and heating medium on browning color Original Research Article

Samples of red sea bream (Pagrus major) were grilled under radiant (far-infrared radiation, FIR) and convective (superheated steam, SHS) heating. The temperature and color (CIE L∗, a∗, and b∗ values) of the sample surface were monitored over time, using SHS, dry air, and N2 as heating media. The rate of L∗ changes was evaluated by treating the browning reaction as first-order. Color changes based on a∗ and b∗ values were effectively correlated with the L∗ value, using empirical equations. A slower reduction in L∗ for heating with SHS rather than FIR was obtained, probably because of different activation energies (31.5 and 50.7 kJ mol−1) and frequency factors (8.2 and 4759 s−1). The order of reductions in L∗ was dry air > N2 image SHS. The absence of O2 in the heating medium could be the reason for the delay in the browning reaction during heating using N2 and SHS.