Effects of different heating conditions on the texture and extracts of the meat from each part of the yellowtail Seriola quinqueradiata

We investigated the effects of different heating conditions on the texture and extractive compounds of meat derived from each part of the yellowtail Seriola quinqueradiata fish. Heating conditions had a tendency to affect the hardness and sample thickness of the dorsal ordinary muscle (OM) and dark muscle (DM). Heating did not significantly affect the inosine monophosphate level in OM. However, low-temperature/long-time (LTLT) heating (63 °C for 30 min) decreased these levels in DM compared with unheated sample. The hypoxanthine levels in OM and DM subjected to LTLT heating were also significantly higher than those of unheated samples. Free amino acid and ammonia levels in each part remained unchanged after heating, except for the levels of three amino acids in DM. OM and DM with LTLT had higher and lower taste-active values of equivalent umami concentrations than with high-temperature/short-time heating (85 °C for 90 s and 75 °C for 60 s), respectively. Therefore, under LTLT, yellowtail meat has a more tender texture owing to less shrinkage, and umami intensity is much stronger in OM but weaker in DM.