The Formation Of Volatile Aromatic Compounds Of Roast Beef Based On Enzymatic Hydrolysis And Directional Maillard Reaction

Due to the good color,aroma and taste,traditional roast meat is favored by domestic and foreign consumers.However,meat products processed under conditions of high temperature could easily produce heterocyclic amines,3,4-benzopyrene and other carcinogenic substances.In this experiment,beef hydrolyzate was used as a substrate based on the principle of Maillard reaction to develop substrate mixture that can generate good color and special barbecue flavor under mild conditions(120 ?)By heat drying technology field,green,healthy,safe and tasty roast beef products were made.The research contents and results were as follows:1.Preparation of substrate mixture based on the directional Maillard reactionFirstly,the condition to prepare beef enzymatic hydrolysis was optimized by orthogonal experiment:ground beef 10 g,concentration of substate about 30%,reaction temperature 50 ?,pH 6.5,m(Flavourzyme):m(protamex)= 1:1,the amount of enzyme content of 8%,hydrolysis time 5 h;then beef hydrolyzate was used as one of the substrate to determine the ratio of substrate mixture by factorial experiment design:beef hydrolyzate 20 g,glucose 1.0 g,glycine 0.8 g,thiamine 0.3 g,reaction temperature 120 ?,pH 7.5,time 90 min.Gas chromatography-mass spectrometry analysis showed that the characteristic flavor of roast beef with relatively high amount in this model system were 2-methyl-3-furanthiol,2-methyl tetrahydro-thiophene-3-one and bis(2-methyl-3-furyl)disulfide.The model system featured with high degree of browning that the absortion was up to 0.263.Sensory evaluation demonstrated that the roast beef flavor is pure and rich.2.Optimization of marinating conditions and drying parameters of roast beefThe amount of salt,sugar and spices was selected as parameters of marinating condition and sensory evaluation was employed as an indicator.The results showed that:salt 1.2%,sugar:salt= 1:0.4,spices concentration 4%(w/w,based on the starting weight of meat),product was characterized with good taste and highest sensory score.L27(3)13 orthogonal test results showed that:the best processing parameters for roast beef were:the first phase of the drying temperature 90 ?,time 20 min;the second stage drying temperature 130 ?,time 50 min.Under these conditions,the product has the best hardness,elasticity,chewiness and sensory evaluation.3.The determination of heterocyclic amines,3,4-benzopyrene and volatile aromatic compounds of beef roasted under low temperatureBy high performance liquid chromatography-mass spectrometry and HPLC were applied to determine the heterocyclic amines and 3,4-benzopyrene respectively,in roast beef products.The results showed that:cold roast beef MeIQx,Trp-P-2,Trp-P-1,Norharman and Harman were detected,a total amount of 38.628 ?g/kg,significantly lower than the traditional roast beef samples with heterocyclic amine content(112.048 ?g/kg)(p<0.05);3,4-benzopyrene content was 0.036 ?g/kg,significantly lower than the German standard 1 ?g/kg(p<0.05);by use of solid phase micro extraction GC-MS assay,traditional roast beef and beef roasted under low temperature,volatile aromatic compounds of the former were 54 kinds,while the latter 61 kinds,including hydrocarbons,alcohols,aldehydes,ketones,carboxylic acids,esters,phenols,furans,thiophenes,thiazoles,pyridine type,oxazole piperidine,etc.,wherein n-butyl-furan,2-pentyl furan,3-methyl-furan-tetrahydronaphthalene carboxylic acid are contributors to the strong roast beef flavor although the amount is not high.