Preparation Of Corn High Fischer Ratio Oligopeptide And Physiological Function Study

Corn gluten meal（CGM） is a by-product in the process of wet production of corn starch.CGM contain60%protein, it is mainly used in feed due to its poor taste, so its practical valueis not high. CGM can be prepared for the high Fischer ratio oligopeptide by enzymatichydrolysis. And high Fischer ratio oligopeptide has many biological activities, such asantifatigue, hangover, the function of hepatic encephalopathy treatment.Response surface methodology based on Box-Benhnken experimental design wasemployed to optimize conditions for the dual-enzymatic hydrolysis of corn gluten meal toobtain the maximum degree of hydrolysis. The optimal hydrolysis conditions were found asfollows: pH11.10, hydrolysis temperature55.00℃, substrate concentration112g/L, activityratio of alkaline protease to neutral protease5:1, total enzyme dose48000U/g, and hydrolysistime120min. Under these conditions, the actual degree of hydrolysis was30.23%, and thepredicted value was30.84%. The dual-enzymatic hydrolysis process was simple and provideda high degree of hydrolysis.In order to hydrolyze corn gluten meal efficiently, combinations of two or three out ofthree hydrolysis enzymes （protex6L, protex7L and papain） were used and the processparameters were optimized in this paper. The degree of hydrolysis of corn gluten meal wasassayed by using pH-stat method. The ratio of enzymes was optimized and the effect ofmulti-enzyme hydrolysis was compared with that of single-enzyme hydrolysis. The resultshowed that the optimal ratio of protex6L and protex7L was3:1, protex6L and papain was6:5,protex7L and papain was1:1, and the optimal ratio of protex6L, protex7L and papain was4:1:1.The degree of hydrolysis and soluble protein content of multi-enzyme hydrolysis approximately was equal to single-enzyme hydrolysis, but multi-enzyme hydrolysis wastimesaving.Using pH-stat method to determine the degree of hydrolysis of corn gluten meal ofAlkaline protease to measure the impact of eight kinds metal ions on the hydrolysis. Theresults showed that Ba²⁺and Li⁺have little impact on the Alkaline protease, Mg²⁺, Mn²⁺, Ca²⁺and K⁺have a promote impact on the Alkaline protease, Cu²⁺and Zn²⁺have a inhibit impacton the Alkaline protease. Mg²⁺4mmol/L, Mn²⁺4mmol/L, Ca²⁺4mmol/L and K⁺6mmol/Lhave an activation to the hydrolysis of corn gluten meal by Alkaline protease. With the moreconcentration of Cu²⁺, Zn²⁺the inhibition to alkaline protease is greater.Preparate high Fischer ratio oligopeptide by activated carbon adsorption of corn glutenmeal hydrolysate, with OD₂₀₈/OD₂₆₉as the index, through the single factor experiment andresponse surface methodology, the activated carbon adsorption conditions were optimized andthe optimal conditions were pH1.97, adsorption time2.92h and ratio of solid to liquid1:8.84.On this condition the OD₂₀₈/OD₂₆₉was11.9857.After activated carbon adsorption, ion exchange, classification of ultrafiltration, eachindex was measured in the experiment process. The enzyme activity of hydrolysate was16.50U/mL, the enzyme activity of hydrolysis residue was19.46U/g. The molecular weight ofoligopeptide after ultrafiltration was624-120. The Fischer ratio of oligopeptide was21.92.The content of amino nitrogen of corn gluten meal hydrolysis was13.12mg/mL, after theadsorption the content of amino nitrogen in hydrolytic solution was5.04mg/mL and after ionexchange the content of amino nitrogen of hydrolysate was3.83mg/mL, the content of aminonitrogen of hydrolytic solution was2.71mg/mL after ultrafiltration. The total protein contentof corn gluten meal was0.948g/g, and corn gluten hydrolysate was9.625mg/mL, the recoveryrate was60.16%, protein content of hydrolysate after adsorption was22.604mg/mL, therecovery rate was15.86%, total protein content after ion exchange in hydrolysis was17.675mg/mL, the product recovery rate was12.40%, after ultrafiltration the protein contentof hydrolysate was9.625mg/mL and rate of recovery was6.75%.Used the multi-enzyme hydrolysis corn gluten meal, the hydrolysiate after active carbon adsorption aromatic amino acids, filtering, ultrafiltration, concentration to prepare highF ratio oligo-peptide. The function of anti-fatigue and curative effect of treating acutealcoholism.of high Fischer ratio oligo-peptide was appraised. The results indicated thatcomparing test groups with the control groups, the ebriety time of low, moderate andhigh-dose groups were increased30.06%,39.35%and49.97%respectively. The ebriety ratewere decreased20%,40%and80%respectively. Sober-up times were shorter12.16%,22.32%and23.04%respectively. The death rates were decreased50%,50%and100%respectively. The activity of ALT in serum in low, moderate and high-dose groups comparingwith the control groups was decreased16.03%,24.34%and26.71%respectively. Theactivities of AST in serum were decreased27.65%,34.40%and34.81%respectively. Thecontent of MDA in liver tissue were decreased26.45%,32.23%and33.06%respectively. Theactivities of SOD in liver tissue were increased2.83%,5.37%and9.28%respectively. Theactivity of CAT in liver tissue were increased4.78%,12.32%（p<0.05） and14.86%respectively. The high F ratio oligo-peptide has a good curative effect of treating acutealcoholism. Compared with test groups with the control groups, the swimming times in thelow, moderate and high-dose groups increase27.69%,106.16%and138.47%respectively.Liver glucogen contents were increased10.01%,35.77%and101.43%respectively. Muscleglucogen contents were increased62.63%,118.18%and178.79%respectively. Urea nitrogencontents were decreased3.94%（p<0.001）,12.81%（p<0.05） and37.60%（p<0.01） respectively.The lactates contents were decreased1.26%（p<0.05）,9.97%and15.44%respectively. Thefunction of anti-fatigue of high Fischer ratio oligopeptide is proved.