Heating duration alters the low-molecular-weight compound profile of fish muscle, with pyruvic acid as a potential marker of thermal history.

This study used gas chromatography-mass spectrometry (GC-MS)-based metabolic profiling to assess the effects of heating duration on low-molecular-weight compound profiles in fish muscle from yellowtail, chum salmon, Alaska pollock, and Pacific herring and to identify species-independent heating history markers. Heated samples were analyzed by GC-MS, followed by compound annotation and semi-quantification. Orthogonal partial least squares regression analysis indicated that heating and extended heating altered the low-molecular-weight compound profiles of fish muscle. Pyruvic acid and glycolic acid, which showed high variable importance in prediction scores, were identified as candidate heating history markers. Quantitative analysis showed that both compounds increased with heating duration. Notably, pyruvic acid showed coefficients of determination to be ≥ 0.8 for all four fish species, supporting its potential as an effective species-independent marker of fish muscle heating history.