Due to factors such as the growth environment and endogenous proteases, freshwater fish generally have a strong fishy and earthy odor, which severely affects product quality and sustainable industrial development. In traditional boiled fish, the spicy flavor can effectively mask the fishy odor using strong spices. However, in non-spicy flavor types such as tomato- or sauerkraut-flavored boiled fish products, the deodorizing effect is insufficient, which limits market acceptance. In recent years, emulsion embedding technology has provided a new approach for the stable protection of flavor substances, and the construction of thermally stable emulsions is particularly promising for solving this problem. Therefore, it is of great theoretical and practical value to screen natural spices rich in the above-mentioned key deodorizing components, optimize the extraction process, and use a thermally stable emulsion to embed the ingredients for evaluating their deodorizing effect on boiled fish. To investigate the effect of emulsifying and embedding natural spices on the removal of fishy substances in freshwater fish. This work used typical spices (red pepper, green pepper, star anise, cumin, bay leaf, chili, and cloves) as raw materials. The main flavor components were screened and the extraction process was optimized using HS-SPME-GC-MS. Subsequently, combined with odor activity value (OAV) analysis, the effect of emulsified natural spice deodorizing ingredients on removing fishy odor from freshwater fish was explored. The optimal extraction conditions for natural deodorizing spice ingredients were as follows: a 1∶1∶1 mass ratio of green pepper, star anise, and red pepper, a 4∶1 oil to spice quality ratio, an extraction temperature of 130 ℃, and an extraction time of 15 min. A thermally stable emulsion was used to embed the characteristic aroma substances of the ingredients. The resulting emulsion deodorizing ingredient was rich in myrcene (72.75 μg/g), limonene (245.56 μg/g), linalool (590.46 μg/g), and anethole (551.45 μg/g). The boiled fish cooking system was taken as the research object to explore the influence of the amount of emulsion deodorant ingredients on the removal of fishy odor. Results showed the content of aldehydes and 1-octen-3-ol related to fishy odor in boiled fish decreased significantly with the increase of ingredient addition. At an addition level of 60 g/L, the content of fishy substances was reduced by more than 90%, and the deodorizing effect was significantly better than that of an equal amount of tomato-flavored boiled fish seasoning. Furthermore, the thermally stable emulsion achieved a good sustained-release effect on the main aroma substances in the ingredients and effectively inhibit the generation of fishy substances of fishy substances in the boiled fish system.

The core deodorizing components of the natural spice deodorizing ingredients developed in this study were myrcene, limonene, linalool, and anethole. The emulsion-based deodorizing ingredient exhibited an obvious deodorizing effect on the boiled fish system and effectively controlled the release of the key aroma compounds.