Study On The Preparation Of Enzymatic Hydrolysate Of Decapterus Maruadsi Proteins And Maillard Reaction

Decapterus maruadsi is one of the most important marine fishes in China with high yield,small body and plenty of many kinds of nutrition etc..The processing of Decapterus maruadsi is still mainly concentrated in the chilled sales,dried fish,feedstuff and other primary processing products which are low value-added products.The rich resources in Decapterus maruadsi have not been fully utilized.To a certain extent,that restrict Decapterus maruadsi processing industry development.In this subject Decapterus maruadsi was taken as the main research object,using the biological enzymolysis technology to produce decapterus maruadsi enzymatic hydrolysate and optimize hydrolysis process,and studying on producing process on the basis of Maillard reaction to obtain reaction products with rich meat flavor.And that offer new ideas and theoretical support for the development and utilization of decapterus maruadsi resources.The main research contents and results are as follows:1?The best protease to treat Decapterus maruadsi was screened through the comparison and the study of the effects on different proteases(papain,tryptase,trypsin and complex protease)and investigated by using the degree of hydrolysis and protein recovery as the index.The results showed that the hydrolytic degree and the nitrogen recovery rate2?were the highest in the enzymolysis solution treated by compound protease.Thus the compound protease was selected as the enzyme for subsequent experiments.2?The hydrolysis conditions of Decapterus maruadsi was optimized by studying the Protamex Protease,and the effects of dosage of protease,time,hydrolysis temperature on ratio of material to water with Response surface methods.The result shows that the optimal hydrolysis conditions were as follows:dosage of protease 5030 U/g,hydrolysis for 3.5 h,hydrolysis temperature in 50? and ratio of material to water of 1:5.Under these optimal conditions,the DH was 13.94%,indicating that the actual test values were basically consist with the forcast values.At the same time,the mathematical regression model of the degree of hydrolysis(Y),enzyme addition(A),enzymolysis time(B),enzymolysis temperature(C)and solid-liquid ratio(D)were obtained:Y=14.03+0.39A+0.13B+0.26C-0.072D+1.99AB+0.16AC+0.84AD-0.92BC+1.18BD+0.79CD-3.52A2-3.16B2-4.51C2-3.33D~23?Under the optimum conditions of enzymatic hydrolysis,the enzymatic hydrolysate of different hydrolysis degree was obtained by controlling the enzymolysis time.The volatile flavor components of the Decapterus maruadsi and the enzymatic hydrolysate of different hydrolysis degree were identified by gas chromatography-mass spectrometry;and the free amino acids in the enzymatic hydrolysate of each treatment group were analyzed by amino acid automatic analyzer.The results showed that the fishy smell in the fish were mainly derived from saturated linear aldehydes and amines 'such as 2,4-heptadienal,heptanal,octanal and nonanal.Enzymatic treatment significantly affect the content and types of aldehyde and hydrocarbon compounds.Enzymolysis time has no obvious effect on the enzymatic hydrolysate of volatile flavor compounds of the type and content.The time of enzymolysis had a significant effect on the total amount of free amino acids in the enzymatic hydrolysate,and the percentage of amino acids in total amino acids was not positively correlated with the time of enzymolysis.4?The effects of the amount of reducing sugar,the amount of amino acid,the reaction time and the reaction temperature on the reaction of the Maillard solution were studied.The orthogonal experiment was carried out on the basis of single factor test.The results showed that the optimum reaction conditions were as follows:the reaction time was 30 min,the reaction temperature was 100?,the amount of amino acid was 3%and the reduction sugar was 6%.5?The volatile flavor compounds of Maillard reaction products(MRPs)were identified by gas chromatography-mass spectrometry(GC-MS).The results showed that 59 kinds of volatile flavor substances were identified in MRPs.The main volatile substances were aldehydes,alcohols,esters,sulfur compounds,furan and pyrazines,among which sulfur compounds,furan and pyridine play a major role in the meat flavor of MRPs.