Objective Fish bones, a by-product of tuna processing, are rich in collagen and essential minerals such as calcium and phosphorus, rendering them highly nutritious. However, due to limitations in aquatic product processing technologies, the potential for high-value utilization of fish bones remains underexploited. The presence of a strong fishy odor in their products significantly affects consumer acceptance. This study aims to address the issue of fishy odor in marine fish processing by-products, such as fish bones and their derivatives.

Methods Bonito bone meal was used as the research subject, with fishy odor intensity serving as the primary indicator. The study first involved screening various deodorizing agents to identify the most effective one. Subsequently, single-factor experiments and response surface methodology were employed to optimize deodorizing process parameters, including deodorizing agent concentration, temperature, and time. Solid-phase microextraction combined with gas chromatography-mass spectrometry was utilized to analyze the volatile compounds in bonito bone meal before and after deodorization.

Results Yeast was identified as the most effective deodorizing agent for skipjack tuna bone powder. The optimal deodorizing conditions were determined to be a solid-to-liquid ratio of 1∶10, yeast concentration of 3.12%, a temperature of 40 °C, and a treatment time of 151 minutes. Sensory evaluation indicated that the treated fish bone powder exhibited no discernible fishy taste. Analysis using solid-phase microextraction and gas chromatography-mass spectrometry revealed a significant reduction in both the quantity and relative content of volatile compounds associated with the fishy odor. Odor substances such as 3-nitrophenyl ethanol, 1-nonene-3-ol, 2, 6-octanediene-1-ol, 9-decyl-1-ol, 2, 4-decadienal, benzaldehyde, 2-nonenal, 2-acetone, hexane, 2-ethylhexyl ester, trans-2-(2-pentenyl) furan, dipicramine, and 2-propenyl-1-amine were completely eliminated. Additionally, the intensity of other odorants such as 1-octene-3-ol, nonaldehyde, caproaldehyde, 3, 5-octendiene-2-ketone, 2-ethylfuran, and 2-amylfuran was significantly reduced. Conversely, the content of desirable flavor compounds, including ionone, nerolaldehyde, cinnamaldehyde, carvone, and ylangolene, was either detected or increased in the deodorized bone powder.

Conclusion Yeast is an effective agent for deodorizing skipjack tuna bone powder and improving its flavor profile.

Significance This study provides valuable technical insights for the deodorization of fish bone powder and similar aquatic by-products, offering important guidance for the high-value utilization of by-products in aquatic product processing.