Abstract:This study focuses on optimizing the preparation process of Pleuronectes platessa bone soup. Based on single-factor experiments，response surface methodology was employed using overall acceptability and soluble protein content as evaluation criteria. Targeted metabolomic analysis of free amino acids and flavor nucleotides in Pleuronectes platessa bone soup was performed using liquid chromatography-tandem mass spectrometry. The results demonstrated that the optimal process conditions were as follows：roasting time of 6 min，simmering time of 70 min，and seasoning addition of 6%. Under these conditions，the prepared bone soup appeared milky white in color and exhibited a rich flavor，achieving an overall acceptability score of 9.2. The measured soluble protein content was 49.02 mg/mL，and there was no significant difference between this result and the predicted value from the model. After process optimization，the total free amino acid content in the soup increased to 1 196.78 μg/mL，representing a 140% improvement compared with the control group. The optimized process led to a significant increase in umami and sweet amino acids，along with an increase in the total flavor nucleotide content to 56.34 μg/mL.