Research On Enzymatic Hydrolysis Of Waste Beer Yeast For Preparation Of Beef Flavor By Maillard Reaction

The objective of this research was to prepare beef flavor using the yeast extraction of waste beer yeast by a series of reactions, mainly Maillard reaction. The results were as follows:1. The results indicated the optimum autolysis conditions were as follows: adding 3% salt as autolysis promter,pH5.0,at 50℃and 10% beer yeast suspension for 24h,the yield of amino acid nitrogen in supernatant was 3.92%,the yield of products was 61.3%。The yield of amino acid nitrogen in supernatant was increased by 3.40% usingβ-Glucanase.2. Study on the effect of yeast aquolysis and product flavor of five proteases, the results showed that the flavored proteinase was the best choice, the yield of amino acid nitrogen in supernatant reached 4.04% and the yield of products reached 64.2%.3. Optimization of the compound enzymolysis process by response surpace methodology(RSM). The optimum condition of salt content, temperature, initial pH and suspension concentration were 2.1%,48℃,6.3 and 10%. The enzymatic yeast hydrolysate which was made under the optimum condition was determined by amino acid analysis machine, and the result showed the content of total amino acid reached 26.14 mg/mL.4.The optimum content of reaction products of Maillard reaction were evaluated by sensory evaluation.The optimum conditions of Maillard reaction were optimized by single factor experiment and response surpace methodology(RSM),Obtained the optimum conditions as follow: reaction time:106min,reaction temperature:101℃, initial pH:5.6.5.The amino acids in yeast autolysis solution were studied using electrospray ionization ion trap mass spectrometry(ESI-MS), six kinds of amino acids have been identified: Lysine,Histidine,Arginine,Aspartic Acid,Glutamine,Tryptophan.6. Flavor components in the beef flavor were isolated and identified by gas chromatography-mass spectrometry(GC-MS).The results showed that some identified compounds made an important contribution to the meat flavor, such as Furfural, 5-methyl-2-furfural,3-ethyl-2-hydroxy-2-Cyclopenten-1-one,Dihydro-2-methyl-3(2H)-Thiophenone, etc.