Unraveling the fishy odor of Laminaria japonica via headspace solid-phase microextraction gas chromatography-mass spectrometry, molecular docking and chemometrics: Key odorant identification and prediction-model construction.

This study aims to investigate the effects of key fishy-smelling compounds in Laminaria japonica on overall flavor and consumer acceptance. Headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) was employed to analyze Laminaria japonica samples from five representative production areas. A total of 118 volatile components were identified, primarily comprising aldehydes, alcohols, ketones, and alkane compounds. Among these, the aldehydes accounted for the highest proportion (23.73%) and were the primary components responsible for Laminaria japonica's characteristic flavor. The sensory evaluation and odor activity values (OAV) were further combined to preliminarily identify (E)-2-nonenal, (E,Z)-2,6-nonadienal, 1-octen-3-ol and nonanal as key fishy odor compounds. Molecular docking and molecular dynamics (MD) indicate that these substances can form stable bonds with human olfactory receptors (ORs) through hydrogen bonding and hydrophobic interactions. And its free energy of formation ranges from -5.1 to -4.6 kcal/mol, which theoretically confirms its olfactory activation potential. A principal component analysis (PCA) and entropy weight method (EWM) model for fishy odor evaluation was successfully constructed based on four key fishy odor compounds. Ultimately, the model's calculated values showed a high degree of consistency with actual sensory evaluation results (R² > 0.97), effectively validating the model's reliability. This study provides core theoretical support for Laminaria japonica quality and flavor processing by identifying key fishy compounds and developing effective predictive models.