Study On Preparation And Debittness Of Corn Sober Peptides

In this study, corn gluten meal as raw material, the response surface methodology were designed to discover optimum conditions of preparing the corn peptide hydrolyzed by Neutrase, Alcalase and Alcalase adding Flavourzyme. Corn peptides were purified by active carbon absorption method. Molecular weight of corn sober peptides mainly distributed by HPLC. Their components were analysed by Amino Acid Analyzer. Finally, study on the function characters of corn sober peptide. The main results are shown as follows:Alcalase adding Flavourzyme was used to prepare the corn peptide from corn gluten meal. The effects of hydrolysis temperature,time,addition amounts of protease and pH on the ratio of inhibitory activities and DH on·OH of corn gluten meal were studied in the process of hydrolysis. Single factor experiment was employed to optimize its hydrolysis craft. The result showed that a maximum the ratio of inhibitory activities on·OH and the optimum of DH was obtained by optimized sequential hydrolysis for2.0h using alkaline protease at55℃and pH8.5with5g/100mL substrate concentration and3%enzyme dose followed by1.5h using Flavourzyme at pH7.0and50.0℃with4%enzyme dose.Alcalase adding Flavourzyme was used to prepare the corn peptide from corn gluten meal. The effects of hydrolysis temperature,time,addition amounts of protease and pH on the ratio of inhibitory activities on-OH of corn gluten meal were studied in the process of hydrolysis. Single factor experiment and response surface methodology were employed to optimize its hydrolysis craft. The result showed that a maximum the ratio of inhibitory activities on·OH of55.67%was obtained by optimized sequential hydrolysis for2.0h using alkaline protease at55℃and pH8.5with5g/100mL substrate concentration and3%enzyme dose followed by1.6h using Flavourzyme at pH7.0and49.3℃with4.11%enzyme dose.Some properties of bitter peptides were changed after enzymatic hydrolysis by proteinase,for example,solubility charactors,heat stability,nutrition.Corn peptides were purified by active carbon absorption method. The experiment results indicated that active carbon absorption could get a good purification. Single factor experiment and response surface methodology were employed to optimize its debitterness craft. The optimal debitterness condition was as follows:pH was3.5, the absorption temperature was29.5℃, the active carbon content was1:12(m:v) the absorption time was2.Oh and OD220/OD280was37.90.Molecular weight of corn peptides mainly distributed by HPLC. the experimental results of HPLC showed that, the moleelar weight of Corn peptides mainly distributed between1356.594Da-3207.308Da. The result of amino acid analysis showed that there were high contents Alanine and Leucine in corn peptides. especially Leucine.The solubility of corn peptides increased greatly, especially in p I, compared to corn proteins. They were all above90%in different pH. The foaming capacity and emulsifying activity of corn peptides were also improved greatly.