Studies On The Change Of Endogenous Enzymes And Protein Of Brewing Barleys During Their Germination

Barley (Hordeum vulgare) is the main raw materials used for beer brewing. And now depend heavily on imports from other counties, so studies on the similar and difference between domestic brewing barleys and imported brewing barleys is important for the sustaining development of malting industry and beer industry.In this paper, changes of the main endogenous enzymes and protein in10different kinds of brewing barleys during germination were studied, and the similar and difference between domestic and imported brewing barleys were also investigated. Results showed that the domestic brewing barleys also have the same potential quality in many parameters with the imported brewing barleys in malt process, and it will give a theoretical foundation for domestic barleys malting process.The main results were as follows:1. The α-amylase, β-amylase, xylanase, protease, catalase, peroxidase and polyphenol oxidase were studies in10different kinds of brewing barleys during germination. The change of endogenous enzymes in domestic brewing barleys are unstable, the activity of prophase in β-amylase, protease and later period of catalase and in polyphenol oxidase were slightly lower, the growth of the activity in peroxidase was faster, all these were disadvance in malting. The growth of protease in domestic brewing barleys was faster during the later period of germination; the growth of polyphenol oxidase in domestic brewing barleys is faster during the beginning of germination. There is no significant difference in the other endogenous enzyme between domestic and imported brewing barleys during germination. The results provided that the domestic brewing barleys also have the same potential quality in many parameters with the imported brewing barleys in malt process.2. During germination, the change of albumins, globulins, prolamins and glutenins were also studied in9domestic and imported brewing barleys and SDS-PAGE results showed that during their germination the content of albumins increase1.116times, the content of globulins increase first and then decrease, finally slightly in a higher level, the content of prolamins and glutenins decrease0.983and1.167times. The composition of albumins and globulins is basically the same in domestic and imported brewing barleys, and the composition of prolamins is evident different, the composition of glutenins is different too. So, prolamins and glutenins can be used for the quality determination of barley varieties.