Preliminary Study On Enzymatic Hydrolysis And Utilization Of Engraulis Japonicus

The paper studied on preparation of protein hydrolysate from anchovy of low-value fish, through its rich source of enzymes and to add the inside of exogenous enzymes on the hydrolysis of anchovy protein in-depth and studied the change of biochemical characteristics in the hydrolysis of anchovy protein process, prepared with the ACE inhibitory activity of anchovy hydrolyzate. Based on the Maillard reaction, improve the flavor of anchovy hydrolysate, laid the foundation for its further processing. Details of this paper were as follows:1.The technology of autohydrolysis was investigated about anchovy. The mathematical model was eastablished for autohydrolysis of anchovy.The results of single factor experiment suggested that 48 hours was optimum hydrolysis time.The result of the orthogonal experiment suggested that the effect from three factors (temperature, initial pH and water addition ratio) was prominent on the content of amino nitrogen in supernatant. The process of autohydrolysis could be predicated well and truly by the mathematical model.The optimum conditions on autohydrolysis were as follows, temperature (57.05), water addition ratio (0.8:1),initial pH (9.00).The results of analyzing the response surfaces showed that the effect from three factors (temperature, initial pH and water addition ratio) had interaction on response value each other. The result of verification test demonstrated that the content of amino nitrogen in autohydrolysis supernatant attained to 0.4259g/100ml.The predicted value of the equation was 0.4377g/100ml.The good coherence lied in between them. The result of autohydrolysis could be predicted well and truly by the mathematical model.The result on the change of biochemistry index proveded that amino nitrogen content, solubility total nitrogen content, etc.in supernatant and the degree of protein hydrolyze were increased gradually during the course of hydrolyzation.The final value of amino nitrogen,total nitrogen,TVB-N content was 0.42g/100ml, 1.21g/100ml,37.00mg/100g respectively, and the DH,the rate of protein recovery was 30%,47.52% respectively. The results fully demonstrate that the endogenous protease in anchovy can be self-catalyzed protein hydrolysis into peptide, amino acid.2.Based on the autohydrolysis of anchovy, compare the effect of hydrolyzing anchovy using six kinds of proteinase with the target of amino nitrogen, then select the best combination of protease is that trypsin,alkaline protease and flavourzyme. In the study of hydrolysis anchovy protein by compound protease, confirming the role of outside source of enzymes can be further increased the content of amino nitrogen in the hydrolyzate, and the degree of hydrolysis increased also. The mathematical model was eastablished for hydrolysis of anchovy by compound protease, the result show that the content of the amino nitrogen was significantly impacted by the three factors (temperature,initial pH,the amount of enzyme).The optimum conditions on hydrolysis were as follows:temperature (49.94℃), ezyme addition ratio (0.4171%), initial pH (7.54).The result of verification test demonstrated that the content of amino nitrogen in hydrolysis supernatant attained to 0.8615g/100mL. The predicted value of the equation was 0.8615g/100mL.The good coherence lied in between them.The result of hydrolysis could be predicted well and truly by the mathematical model.The biochemical changes in the process of hydrolysis anchovy by compound protease was studied. The final value of amino nitrogen,total nitrogen content was 0.86g/100ml,1.58g/100ml respectively, and the DH,the rate of protein recovery was 65%,85% respectively.3.Tyrarriine, putrescine, cadaverine, histamine, spermine, spermidine, agmatine Differences of biogenic amines and ACE inhibition activities between seven enzymic hydrolysate were compared. Seven biogenic amines were detected by the high performance liquid chromatography-post-column derivation-fluorescence detection ethod(HPLC-PCD-FLD),safety of seven anchovy enzyme process was evaluated.The highest biogenic amine was cadaverine,which was about 80-90mg/mL;followed by histamine,putrescine and agmatine;contents of spermine, spermidine and tyramine were the least.The ACE inhibition activities of seven enzymic hydrolysate was determined by high performance liquid chromatography method(HPLC) and influences on ACE inhibition activityof seven enzymic hydrolysate were compared.Result shows that the IC50 value of trypsin hydrolysate was about 5.26mg/mL,which was the highest.Conversely, compound protease hydrolysate had the lowest ACE inhibition activity,the IC50 value was only 9.10mg/mL.These could supply some information to product development based on anchovy enzymic hydrolysate.4.Improve the flavor of anchovy hydrolyzate through the Maillard reaction. Identified the basic system of Maillard reaction and the reaction of the basic parameters with temperature of 120℃,initial pH value of 7.5 system, adding 1.8% reducing sugar,1.0% sulfide conditions, the reaction time of 40min, then get a good anchovy flavor hydrolyzate.Preparation for further processing, such as fish and soy sauce, etc.