Enzymatic Hydrolysis Of Waste Beer Yeast For Preparation Of Amino Acid And Research On Chicken Flavor

The hydrolysis of waste beer yeast by autolysis or with enzymes for preparation of hydrolysis liquid with amino acids were investigated. The fitting technology were confirmed by experiments and the 4.0 % of amino nitrogen was obtained. The results showed that hydrolysis efficiency of flavourzyme was better than that of papain or neutral protease comparing with the three proteases. The effects of hydrolysis temperature, time, pH and adding amount of the flavourzyme on yield of amino nitrogen and product were studied, and the optimization conditions were as follows: 10 % beer yeast suspension, pH 5.0, adding flavourzyme 1.6 %, temperature 50℃and hydrolysis time 30 h, and the 5.9 % of amino nitrogen , the 59.7% of product were obtained according to the technological conditions. 17 kinds of amino acids were identified using analysis meter of amino acid, and the total concentration of amino acids was 36.89 mg/mL, and the main amino acids were Glu,Ala,Thr,Leu,Arg,Gly, et al. These amino acids were important in Maillard reaction for preparing meat flavor.Analysis of I+G by HPLC was researched. Better separation was gotten when pH was increased. Improvement of flow rate and debasement of concentration did good to shorten separation time. The fitting conditions of mobile phase were: 0.05 mol/L KH2PO4(pH=4.35~5.65), velocity of flow 1.0 ml/L. Separate I+G from hydrolysis liquid with preparative chromatogram. The purity of product was 97.2% and the 0.024 g/L of IMP, the 0.076 g/L of GMP were obtained.Prepared chicken essence by Maillard Reaction with waste beer yeast hydrolysis liquid and reducing sugar. The preparation conditions of reaction techincs were optimized by central composite design. The optimized conditions of preparation of Maillard Reaction are: the reaction temperature is 121.9℃, the reaction time is 50 min and pH is 6.4.The chicken essence was of full-bodied chicken flavor, 40 kinds of compounds were identified using GC-MS. The main compounds were 2-Methyl-3-furanthiol, (z,z)-2,4-Decadienal, 2-ethyl-3-methyl-Pyrazine, Cis-11-hexa decenal et al, which were contributed to chicken flavor.