| Fish oil was extracted by enzymatic hydrolysis method and diluted alkaline hydrolysis method respectively using tilapia as raw material. The optimal extraction processes of the two hydration methods were determined by single factor experiment and orthogonal experiment. Fatty acid compositions of fish oils were analyzed by GC. The results showed that the optimal extraction conditions of fish oil by diluted alkaline hydrolysis method method were obtained as follows: solid-liquid ratio 1∶3, pH 7.5, hydrolysis time 30 min, salt dosage 2.5%, salting out time 25 min, hydrolysis temperature 65℃.The optimal extraction conditions of fish oil by enzymatic hydrolysis method were obtained as follows: solid-liquid ratio 1∶3, enzyme dosage 0.6%, pH 9, enzymatic hydrolysis temperature 55℃, enzymatic hydrolysis time 2 h. Under the optimal conditions, the oil extraction rate and n-3 unsaturated fatty acid content of diluted alkaline hydrolysis method were （32.13±0.07）% and （5.192±0.280）% respectively, higher than those of enzymatic hydrolysis method((28.91±0.18)%, （4.991±0.099）%). |
