Efficient Preparation Of Corn High Fischer Ratio Oligopeptide And By-product Recovery

In this study, the further optimization of the process on the basis of preparing high fischer ratio oligo-peptide is done, and carryed on recovery of aromatic amino acids. The papper provids an experimental basis to achieve efficient preparation of high fischer ratio oligopeptide.CGM are pretreated by three ways: α-amylase, high-pressure steam and ultrasonic. And enzymatic hydrolysis is carried out under optimum conditions to verify its pretreatment effectiveness. The optimum condition of α- amylase pretreatment as follows: CGM gelatinized, cooling, substrate concentration 0.13 g/mL, enzyme dosage 100 U/g, hydrolysis temperature 65℃, pH 7.00, hydrolysis time 100 min. The degree of hydrolysis of pretreated CGM under optimum hydrolysis condition is 48.14%, it increased by 59.21% compared to30.23% that the degree of hydrolysis of non-pretreated CGM. After ultrafiltration, the protein content of hydrolysate was 28.70 mg/mL and the rate of recovery was 20.13%. It increased by198.22% compared to 6.75%The optimum condition is obtained with high pressure steam pretreatment as follows:115 ℃, 0.07 Mpa, 150 min, the degree of hydrolys is 48.16%, it increased by 58.12%compared to CGM without pretreatment. And after ultrafiltration, the protein content of hydrolysate is 24.20 mg/mL and the rate of recovery is 16.97%. It increased by 151.40%compared to 6.75%.CGM is pretreated by ultrasonic. The optimum conditions for pretreatment of CGM:concentration of CGM 112 g/mL, ultrasonic power 600 W, time 20 min, the degree of hydrolysis under optimum conditions after pretreatment is 40.12%, it increased by 32.72%compared to CGM without pretreatment. And after ultrafiltration the protein content of hydrolysate is 24.5 mg/m L and the rate of recovery is 17.18%. It increased by 154.52%compared to 6.75%.Experiment on CGM of immobilized enzyme hydrolysis is studied. CGM protease is immobilized using of sodium alginate, using the single factor experiment and response surface experiments to obtain the optimal immobilized conditions as follows: the concentration of CaCl2 is 3.02%, the concentration of sodium alginate 2.62%, pH 10.01, timeis 2 hours, the amount of enzyme is 80000 U/g, the enzyme activity recovery rate is 64.37%,the expected value model is 64.91%. The CGM is cyclic hydrolysised by the immobilized enzym, and protein content is 6.23% after 3 times hydrolysis, and protein hydrolysis rate of CGM is 89.91%. This method can effectively improve the utilization rate of protein, and the cost is low, it has a broad space for development.In the experiment, desorption recycling study on aromatic amino acid of activated carbon adsorption in the process of preparation of high Fratio oligo-peptide is done. Optimized by single factor and response surface experiments about dsorption conditions: concentration of NaOH 5.42%, temperature 25.75 ℃, activated carbon concentration 0.12 g/mL. The desorption rate is 50.40%, and the model of the expected value is 51.41%. Using HPLC to analyze desorption solution. The content of amino acid is 0.6189 mg/mL, among them Phe0.3000 mg/mL, Tyr 0.2098 mg/mL, Trp 0.0493 mg/m L. And the content of aromatic amino acid accounted for 91.82%. The study opens a new way for recycling byproducts in the process of preparation high fischer value oligopeptide.