Study On Barley Protein Glycation And Oxidation Resistance

Barley is the main raw material for beer brewing, a series of reaction generated during the barley processing must be effectively controlled and tested to ensure the taste and flavor of beer. Barley protein is saccharifed during beer production process, so the study of protein glycosylation has important significance for the production of beer, beer producers and brewing science researchers are very concerned about beer flavor stability and aging issues, most barley soluble protein will eventually enter the finished beer. Based on the above, the experiment using wet modification method to study the characteristics of barley protein glycosylation product, DPPH radical scavenging method and the OH radical scavenging method were used to detect the antioxidant activity of barley soluble proteins,and exogenous substances were added to observe the changes of the antioxidant activity of barley protein.Finally, the theoretical analysis was carried out. The main contents are as follows:(1) analysis of the differences between the antioxidant activity of different varieties of barley seed proteins (2)compare the differences in the anti-oxidative activity between the inositol exogenously addedbarleyand the blank of barley during the process of germination.(3)barley proteinmolecular size were classified by ultrafiltration device, and the antioxidant activity of barley protein of different molecular weight were respectively measured; protease enzyme activity between the barley adding inositol and the barley without inositol were compared during the process of germination.(4) the optimal processing of protein glycosylation were explored through the orthogonal experiment.The barley protein glycosylation is studied. The thermal stability, grafting of the protein, degree of browning reaction and protein content after the reaction of barley protein glycosylation complexes with glucose, fructose, maltose, lactose were analyzed. (5) Study on the effect of inositol on the indicators of the barley malt.Experiments showed that:(1)The antioxidant activity of barley water soluble protein increased in barley seeds during germination,adding inositol can increase the antioxidant activity of water soluble protein malt.(2) By comparing the different varieties of barley shows that antioxidant activity of barley protein Gander>antioxidant activity of barley protein Metcalfe>antioxidant activity of barley protein FAQ>antioxidant activity of barley protein Ganpi Four.(3) According to the orthogonal experiment that the optimum conditions of barley proteins and reducing sugars in the Maillard reaction is mass ratio of protein and sugar=1:2, pH 9,temperature 90℃.(4) By comparing of four different barley protein and sugar complex reactions shows the maximum degree of grafting of barley protein complexes with fructose, the minimum degree of grafting of barley protein complexes with maltose. In the study of antioxidant properties of barley glycoprotein,four kinds of glycoproteins have improved scavenging DPPH,strongest antioxidant capacity of fructose sugar protein, weakest antioxidant of glucose glycoprotein.(5) Add the inositol can improve the content of amino acids in mashing wort,serine content increased by 15.8%, histidine content increased by 14.4%, arginine content increased by 19.7%, proline content increased by 9.4%, tyrosine content increased by 13.5%,leucine content increased by 13.6%.