Study On The Comprehensive Utilization Of Viscera Of Freshwater Fish

The visceral organs of freshwater fish are rich in oil and protein resources and have high utilization value.In this paper,fish oil was extracted and refined from freshwater fish viscera,and the sensory and physicochemical properties of crude and refined fish oil were analyzed and evaluated.The contents and results of the study are as follows:?1?Extraction and Refining of oil from freshwater fishThe crude fish oil was extracted by potassium method,hot water method and enzymatic method.Then the crude fish oil was refined and the sensory and physicochemical properties of crude fish oil and refined fish oil were analyzed and evaluated.After refining,the color of fish oil becomes lighter,the smell of fish is reduced,and the transparency is improved;the physical and chemical indexes such as moisture and volatile matter,acid value and peroxide value are obviously improved.In general,the fish oil extracted by the three methods can reach the secondary refined fish oil standard except iodine value after refining.?2?Study on enzymatic hydrolysis of residue from fresh water fish after extracting oil from visceraFirstly,the residual residue of visceral fish oil extracted by the above three methods of potassium method,hot water method and enzymatic method was determined as the basic components,and the residue after oil extraction by hot water method was finally determined as the raw material.Then,five enzymes,neutral protease,flavor protease,trypsin,alkaline protease and papain,were used as the experimental enzymes,and the residue was enzymolyzed under the optimum conditions respectively.The degree of hydrolysis was used as the index to determine the flavor protease as the optimum enzyme.And then through the single factor experiment,explore the flavor protease digestion guts residue after oil extraction of the optimal p H,temperature,enzyme amount and digestion time,again through the response surface method Box-Behnken optimize the single factor experiment results,finally be digestion guts residue after extracting fish oil the best process conditions of p H 7.5,the heating temperature of 65?,wind pepsin amount 2010 u/g,enzymolysis time 4.15 h,the hydrolysis degree of up to 16.6225%.?3?Study on maillard reaction after enzymatic hydrolysis of viscera residueMaillard reaction was performed with xylose,lactose,fructose,glucose,sucrose,etc.The most suitable sugar for xylose reaction was determined by sensory evaluation,ammonia nitrogen loss rate,and Browning degree A420nm.And then through the single factor experiment to explore the xylose content,p H value,reaction temperature and reaction time on the influence of the maillard reaction,and through the Box-Behnken optimization and Design-Expert.V8.0.6 comprehensive analysis to get the best technology of maillard reaction conditions for xylose content 2.9%,initial p H 7.4,the reaction temperature 99?,the reaction time of 63 min,the maillard reaction products under the condition of ammonia nitrogen loss rate was 6.32%,A₄₂₀nm 0.190,sensory score of 9.7,with good color and flavor.?4?Study on preparation of fish sauce by fermentation of the residue of fresh water fish viscera after oil extractionBy hot water method and enzymatic hydrolysis after the fish oil remaining residue as material,using A,B two different ways for fermentation,and regularly test the p H of the fermentation process,amino nitrogen,total acid,Na Cl and TVB-N value,salt-free solids,total nitrogen content and 8 indicators of non enzymatic Browning index,after the comparative analysis found that two kinds of raw materials obtained by two methods of four types of fish sauce product of amino acid nitrogen content were higher than the primary standard of fish sauce,fish sauce industry standard of total nitrogen content in addition to the enzyme B level 3 fish sauce standard,the other three types of fish sauce all reach the standard level of fish sauce.In general,it is feasible to ferment the residue of fish viscera after oil extraction to prepare fish sauce.In the four cases,the best quality of fish sauce was obtained from the residue after oil extraction by hot water fermentation method A,followed by the residue after oil extraction by enzymatic fermentation method A.The results of this paper can provide a good research basis and technical support for the processing and utilization of fish viscera.