Abstract:Hippocampus abdominalis，as a newly cultured species suitable for large-scale aquaculture，holds significant commercial potential. However，the current prevalence of natural drying methods for seahorses leads to poorly controlled product quality，highlighting an urgent need to develop standardized drying processing technology. This study investigated the effects of different drying methods—hot air drying （HAD），vacuum drying （VD），-20 ℃ freezing-vacuum lyophilization （L-20），-80 ℃ freezing-vacuum lyophilization （L-80），and liquid nitrogen freezing-vacuum lyophilization （L-LN）—on the drying characteristics and quality of H. abdominalis. The results indicated that vacuum lyophilization （L-20，L-80，L-LN） effectively inhibited discoloration and shrinkage during drying. The color difference （ΔE） values for the L-20，L-80，and L-LN groups were 78.39%，74.89%，and 78.59% lower than that of the HAD group，respectively. The shrinkage rates for all three lyophilization groups were below 2.0%，while those for the HAD and VD groups were as high as 14.0% and 17.0%，respectively. The drying methods significantly affected the water distribution within H. abdominalis.The low-field nuclear magnetic resonance analysis revealed that the hydrogen proton signal intensity in the LLN group at the Ⅳ drying stage was 35.26%，74.97%，68.77%，and 69.67% lower than that in the HAD，VD，L-20，and L-80 groups，respectively. The Fourier transform infrared spectroscopy results further showed that the relative content of β-turns in the L-LN group was 15.02% and 5.12% lower than that in the L-20 and L-80 groups，while its α-helix content was 17.20% and 13.47% higher，respectively. Concurrently，the total protein，unsaturated fatty acid，and cholesterol content in the L-LN group were 12.90%，49.93%，and 11.07% higher than those in the HAD group，respectively （P＜0.05）. In conclusion，vacuum lyophilization endows H. abdomi-nalis with excellent appearance，maintains higher nutritional value，and ensures better flavor quality. Furthermore，a lower freezing temperature prior to lyophilization results in better product quality.