Comparative analysis of the non-volatile metabolites and taste profiles of the four famous freshwater fish raw materials in China

Four famous freshwater fish in China are renowned for their high production among freshwater species and are much-prized as sought-after delicacies. However, the distinct taste profiles and the specific associated taste substance of these carps remain poorly understood. This study primarily investigated the taste profiles and associated taste compounds, along with non- volatile metabolites of these four species using ultra performance liquid chromatography-mass spectrometry (UPLC-MS) combined with electronic tongue technology. Results revealed that <i>Mylopharyngodon piceus</i> (MP) exhibited significantly higher levels of total free amino acids and adenosine triphosphate (ATP) compared to the other three fish species (<i>p</i> < 0.05), with contents reaching approximately 388.90 mg/100 g and 140.88 mg/100 g, respectively. <i>Ctenopharyngodon idella</i> (CI) and MP possessed richer tastes compared to <i>Aristichthys nobilis</i> (AN) and <i>Hypophthalmichthys molitrix</i> (HM) based on the electronic tongue analysis. Furthermore, UPLC-MS metabolomics analysis identified 49 key metabolites, highlighting major metabolic pathways including lipid, amino acid, and organic acid metabolism. The findings suggested that variations in taste-related compounds and metabolites within metabolic pathways contribute to the distinct flavor profiles observed among the four famous fish species. This research offers essential insights for aquaculture professionals and researchers focused on enhancing the flavor quality of these key fish species, especially in understanding the regulatory mechanisms involved in flavor development.