Eel Head Enzymolysis And Product Characteristics

Eel head was chose as raw materials in this report, and was conducted by two-step fractional hydrolysis. Alcalase was selected as the first enzymatic protease, and papain was chose as the second enzymatic protease. The best condition of Alcalase enzymolysis was55℃,48AU/kg, pH9.0, and200min. And the best condition of papain enzymolysis was65℃,250U/kg, pH6.5, and240min. The protein hydrolysis degree of eel head was20.80%.Amino acid compositions in the hydrolysates acquired by single protease and composite proteases were analyzed by HPLC, and the flavor scores were assessed. The yield of hydrolysate by single protease enzymolysis was8.35%, and that by composite proteases was16.01%. The flavor score of the hydrolysate by composite proteases emzymolysis was201.77, which was higher than the other one. The hydrolysates were subjected to low temperature cryodesiccation.These two kinds of hydrolysates were added to grass carp surimi. Grass carp surimi was stored at-25℃.The results found that after80days, the contents of salt soluble protein in the hydrolysate of single protease and the hydrolysate of composite proteases groups were34.84%and35.41%respectively, which were higher than those of the blank group and the traditional antifreeze group. The ATPase activity maintained at21.72%and26.27%, and the blank group ATPase activity was only3.32%.DPPH free radicals, reducing activity and ferrous ion chelating activity were used to evaluate the vitro antioxidant activity ability of these hydrolyastes. The study found that both hydrolyastes had a certain antioxidant effect, and the hydrolyaste of composite protease had a better effect than the other.Protease hydrolysis method was one of the effective ways to extract fish oil. Alcalase hydrolysis in200min was the best one compared with steaming extraction, alkali hydrolysis method and enzymolysis by composite proteases. The fish oil acquired by Alcalase hydrolysis was analyzed by physical and chemical method. The result showed that fish oil's acid value was0.442, iodine walu was182.63, peroxide value was4.54, the content of water and volatile substance was0.1623%, and ash content was0.0330%. So this fish oil accorded with level1crude fish oil standards(SC/T3502-2000).Fatty acid composition of oil gained by steaming extraction, alkali hydrolysis method and Alcalase enzymolysis was analysed by GC-MS. Fish oil gained by enzymolysis contained1.84%EPA and8.13%DHA, which was higher than the other kinds.