Study On The Use Of Exogenous Substances To Improve The Quality Of Malt

Malt is the main raw material for beer brewing. The quality of malt directly affects the manufacture and quality of beer. So the methods to improve the quality of malt are explored and researched by people all the time. Exogenous substances are added in the process of steeping of barley which could improve the quality of malt, but the effective, safe and low-cost malting additives still need to be explored. Based on the above reasons, this experiment mainly contents are as follows:(1) The basic indicators of different varieties of barley, steeping degree, alcohol soluble protein degradation ability and malt indexes were determinated;(2) Add riboflavin, mannitol, chitosan in the process of steeping, analysis on the steeping degree, activities of α-amylase, β-amylase, phytase and protease, alcohol-soluble protein degradation ability and the influence of malt index;(3) According to the protease activity and the indicators of malt, additive amount of mannitol was optimized. And mannitol was added in other variety of barley to verificate the effection. GA was added in the process of steeping to compare with mannitol in the effection.Experiments show that: domestic barley protein content is higher than others, but steeping degree is lower after the process of steeping. Although it has better ability of alcohol soluble protein degradation, its protein solubility property has shortcomings. That shows in the library value, α-amino nitrogen and leaching rate were lower than the others.Riboflavin, mannitol and chitosan had improved the quality of malt. Mannitol could improve steeping degree and had a promoting effection of α-amylase,β-amylase, protease and phytase activities. At the same time, mannitol had improved alcohol soluble protein degradation degree. Chitosan increased significantly the activities of α-amylase, β-amylase,the activities of phytase and protease had certain improvement. Riboflavin had a promoting effection for the activities of α-amylase, β-amylase, phytase and protease,meanwhile, it promoted the degradation degree of alcohol-soluble protein. Three kinds of materials had improved the quality indexes of malt,such as library value, α-amino nitrogen and leaching rate, saccharifying power.C hitosan significantly improved the saccharification.Riboflavin could affect the chroma of malt.In conclusion, three substances improving the quality effection degree was mannitol, riboflavin, chitosan in turn.20 mg mannitol adding in the steeping of 100 g barley was optimal, the activity of protease and the indicators of malt would be better in this time. And high concentration of mannitol had adverse impact on the activity of protease and the indicators of malt. Mannitol had improved enzyme activities of different varieties of barley and the quality of malt,and the trend of effection was comparatively unanimous. Through the comparison of the effection between mannitol and GA, determined the mannitol had significantly improved the quality of malt and without adversely affection to the index of malt.Also,it has food security and low price.So mannitol is suitable for using as malting additive.