The Study On Barley Heat-stable Proteins

Barley as the main cash crops, the planting area of it is increasing. Barley can be used asforage, food and production, which has a high value. Our country is a big nation ofbeer-consumption, every year per capita beer consumption is growing, but still lagged behindthat of the world average. With the development of our society, beer consumption will growincreasingly, followed by increasingly high demand for consumers on the quality of beer.Barley as one of the important raw materials in the process of beer brewing, the characterof the largely plays a decisive role in the quality of the beer largely. Barley quality has a directimpact on the subsequent fermentation process, the process of saccharification, filtration, andchroma, taste, foam durability of finished beer. Proteins of barley also have a crucial impacton malt and beer. So researches on barley proteins is very necessary, especially all stages ofprotein during germination, which will be very helpful for us to understand the mechanism ofgermination of barley.For these reasons, our experiments use the barley Gairdner (Product of Australian) whichis very common on barley study, we had tried numerous of methods for extraction of barleysoluble proteins, such as the buffer method, the lysis method, the buffer-phenol, andeventually we established buffer-phenol method. By using the optimized method, proteinextraction and sample preparation methods could be achieved. After that barley water-solubleproteins during germination process were separated by2-DE technique, we had established a2-DE procedure for barley and malt research, made a comprehensive analysis of heat-stablewater-soluble proteins in barley.In this study, we analyzed the changes of proteins during germination with proteomicapproaches, the result shows that: the extraction temperature is20.143℃,liquid ratio is6.025mL/g, the extracting time is118.364min, they are conditions for a good sample.Buffer-phenol method of barley proteins have good reproducibility and operability. The resultof comparison for domestic barley with foreign barley shows that trend of barley heat-stableprotein is same, but the content of the protein Z is different, Domestic barley with foreign barley varieties comparison results showed that the thermal stability of protein in Barleyduring germination trend basically the same, but due to the difference between total nitrogencontent of the protein Z also somewhat difference, the protein species of Kenpi II is more thatof Gairdner.The results of infrared Spectroscopy for green malt and malt shows that thenumber of hydrogen bond are increasing, the Differential Scanning Calorimeter (DSC/DTA)shows the stability of proteins are reducing, there must be some non-covalent bonds havebeen broken up, or he protein structure of protein have been changed already during thedrying stage.