Study On The Purification, Identification And Simulated Moving Bed Chromatography Technology Of ACE Inhibition Peptides Of Mung Bean Dregs

In order to fully utilize the protein resources of mung bean and raise the additional value of theprocessed mung beam products，this experiment uses mung bean dregs—the byproducts of mungbean starch—as raw materials to prepare antihypertensive peptides by dint of enzymolysistechnology after pre-processing.Meanwhile,this experiment purifies and identifiesantihypertensive peptides by means of separation and purification technology and bio-massspectrometry. Finally，this experiment implements industrialized separation for the high-activityantihypertensive peptides by dint of simulated moving bed chromatograpHy. Below are themajor contents and conclusions.（1）The processing technologies such as superfine comminution，organic solvent extraction，and enzymolysis are utilized to damage the compact structure of raw materials to remove thesubstances that might influence peptide preparation and purification， such as farinaceoussubstances and lipids. In the experiment of enzyme screening， the inhibition rate and hydrolysisdegree of ACE—an enzymatic hydrolysate—are applied as the indicators to select Alcalase2.4Las the optimal hydrolase.（2）Substrate concentration，PH，temperature and enzyme dosage [E]:[S] are used as singlefactors， and the parameter values of these four factors are determined for the sake of orthogonalexperiment. Additionally，ACE inhibition rate is used as evaluation indicator to determine theoptimal technological condition for preparing ACE inhibitory peptide of mung beam dregs bymeans of enzymatic hydrolysis. The findings show that the greatest ACE inhibition rate willreach75.68%when the hydrolysis time is2h; the PH value is8.0; the temperature is55℃; andenzyme dosage [E]:[S] is1.5/100.（3）In product purification process，the ultrafiltration membranes with the molecular weightcut-offs of5000u，3000u and1000u are separated fractionally to get the constituents withmolecular weight cut-offs of1000u—3000u. Then， these constituents are used to separate resinto work out that peptide’s ACE inhibition rate is80.5%.Then，after preparative RP-HPLCseparation，the separation products of resin are turned into high-activity inhibitory peptide withthe inhibition rate of89.5%. The high-activity products separated through RP-HPLC aresequenced，and the measurement result of tandem mass spectrometry shows that there are three peptide sequences achieving the highest matching ratios， which separately areFLVNPDDNENL，FLVNPDDNENLRII，and KDNVISEIPTEVLDL.（4）According to the experimental results about the antihypertensive peptide purity and yieldof mung beam dregs，the data model and related theories of simulated moving bed are combinedwith single factor experiment to work out that the optimal injection flow velocity，water washingflow velocity1，alcohol washing velocity，and water washing flow velocity2are14.0mL/min，21.0mL/min，12.0mL/min，and26.0mL/min，respectively，when the injection concentrationis14mg/mL. According to the in-vitro simulation test of simulated gastric fluid and simulatedintestinal fluid， high-activity antihypertensive peptides of mung beam are resistant to simulatedgastric fluid and simulated intestinal fluid， highly stable and conducive to reducing bloodpressure.