Study Of Comprehensive Utilization Of Chub Entrails

The entrails of chub are one of the primary by-products of fresh-water fish processing industry. The entrails of chub average content 24.37% oil and 8.67%, the composition of protein including nearly perfect aminophenol, which have grate physiological active and nutritional value. Thus it can be seen that chub entrails are not only oil plant resource but also protein resource. Aqueous enzymatic extraction of fish oil, which based on mechanical and enzymatic breakage of protein structure, was a new way of oil production. The one of advantages of aqueous enzymatic extraction was that oil and hydrolyzed protein of chub entrails could be obtained at the same time. The objective of this dissertation was to exploit a new method to extract fish oil and utilize the protein after extracting oil. In this way the entrails of chub can be complex utilized.The process of aqueous enzymatic extraction of fish oil was established. The results have shown that the yield of free oil depended on the treatment of raw material, the consistency of zymolyte, enzyme preparation, ratio of enzyme, the pH, time and temperature of enzymatic reaction. In this experiment the optimum parameters were as follows. The ratio of water to fish-entrails 1:1, the amount of enzyme 3593U/g, hydrolysis time 3h , the temperature of hydrolysis was 66.8℃, the hydrolysis pH 7.9. Under these conditions , the extraction rate of fish oil was as much as95.5 %.The hydrolyzed proteins were obtained through acticarbon filtration,concentrating and freeze drying. The acticarbon filtration technology was effective to remove fishy smell and impurity at the same time. The hydrolyzed protein powder contented 83.78% protein (or peptide) and also had a little water, oil and so on. Through determining the distribution of the molecular weight for various components in the resulted power. We could know that a majority of hydrolyzed proteins were peptides, only a little were proteins. In addition, composition of peptides concentrated above 5000Da and the composition of aminophenol was nearly perfect which included all kinds of integrant aminophenol.In this project, VE+VC were added in the fish oil as the antioxidant, which has solved the problem of oxidation. Research indicated that added 0.08% VE+VC in the fish oil with the ratio of VE:VC=3:1 can effectively prevent the oil been oxidized in room temperature in a long time.