Studies On Barley Protein Solution And Compairson Of Its Inspection Methods

This thesis takes the soluble protein during barley germinating as the research object,choose three varieties of barley to determine the changes of protein content during barleygerminating, utilize data analysis software Excel to analyze their variation, detect the Kolbachindex of malt which produced by the three varieties of barley and establish a correlation. Theresult indicates that the variation of protein content of barley is in line with the binomialequations after barley entering the stage of germination, therefore the changes of proteincontent during barley germinating can be calculated. Along with the time of germinationextends and when the protein content in the barley storage is within the degression range ofthe protein changes in the trend line, especially more close to its minimum point, the morealbuminolysis decomposes, the higher the Kolbach index of the malt storehouse becomes, andthe barley protein dissolves moderately.In order to further study dissolution and transformation of barley protein, differentconsistency of metal ion chelator EDTA solution is chosen to cultivate barley so as to removethe influence on the protease activity of malt; while the relationship among EDTA, metal ionsand protease activity can analyze the influence of EDTA over the protease activity of malt andthe various protein content, plus the conversion among the various protein components andthe correlation with malt base value, hence a new method which can determine the maltprotein solubility is set up according to the above mentioned. The results show that the EDTAcan maintain the necessary metallic ion of protease activity by chelating, reduce the proteaseactivity of malt mainly carboxypeptidase activity, reduce the conversion of polymer storageproteins into soluble protein, and reduce the Kolbach index. The conversion among four kindsof protein in malt is further analyzed by SDS-PAGE, which shows the enzymecarboxypeptidase has great influence on hordein29.0~97.2kDa and alkali-soluble protein ofabout90.0and53.0kDa and they are decomposed into protein molecular weight about50.0kDa which transfer to the water-soluble and salt soluble proteins and has positive correlation with the malt Kolbach index. After calculation, the barley protein dissolves moderately andthe malt has a highly quality when the content of water-soluble reaches0.193mg/g and above,the content of salt soluble reaches0.25mg/g and above.The traditional method depends on detecting the Kolbach index malt to reflect the barleyprotein solubility only in the amount of soluble protein level of barley, and the operations arecomplex. This thesis on the basis of method which established by research contents cananalyze and calculate whether the hordein dissolved moderately, and the operation is mucheasier.By changing the pH value of barley-soaked water untill alkaline with different varyingdegrees, the changes of the protein content and composition and the Kolbach index of maltare detected, and a relationship between them is established. Analysis shows that theconditions of pH8.0can promote the decomposition of barley storage protein duringgermination of barley and the accumulation of soluble protein content, but at high alkali, itwill inhibit the accumulation of soluble protein, and then reduce the Kolbach index of malt,resulting in malt protein dissolving inadequate.