Study On The Application Of Resin Of Chitosan Cerium Complex Microshperes (RCCM) To Clarify Beer

The beer with complicated ingredients is not stable, and in storage process the precipitation will be produced easily. The main precipitation is the complex of protein and polyphenol, which is caused by the excessive sensitive-polyphenol and sensitive-protein. The beer stability can be improved by removing sensitive-polyphenol and sensitive-protein in industry. The rare-earth element cerium has a good activity in hydrolyzing protein. Chitosan is a nature polysaccharide, and on its molecular chain there are a number of active groups which can chelate metal ions, protein and polyphenols.The objective of this study is application of resin made by the complex of chitosan and cerium to clarify beer. The research results are as follows:1. The resins were made from complexes of chitosan and cerium (RCCM) prepared by opposite crosslinking method in this paper. The color of RCCM is golden, and the diameter of RCCM microsphere is less than 100μm. RCCM were analyzed by ultraviolet spectrum, infrared spectrum and XRD. The results prove that cerium was in RCCM. RCCM were stable in solution with pH 1.0 to 12.0, also RCCM were stable in solution of which the temperature is low than 60℃. Besides, RCCM handled by centrifuge or ultrasound were stable.2. RCCM were applied in beer clarification. The results showed that filtering velocity and diameter length ratio of chromatographic column have little influence on the effect of beer clarification. RCCM can clarify beer which volume is 80 times of the volume of RCCM. The effects of RCCM on beer quality were determined and compared with the finished product beer. The sensitive polyphenols were nearly all adsorbed, the turbidity decreased 97.1%, and the sensitive proteins decreased 48.6%. Meanwhile, the inorganic ions, the flavor compounds, the saccharides and the organic acids had no obvious changes. The amino acids increased 9.84%. Thus the resins made from complexes of chitosan and metal can be used as a new beer clarifier.3. Three process of beer clarification were compared, and the results indict that RCCM and diatomite clarification is better. The beer was clarified by RCCM and diatomite. The results showed that the chroma of beer was 3.535EBC, so the beer belongs to ale. The turbidity of beer was 0.114EBC. RCCM have no effect on the foam and pharmaceutical hops aroma. The contents of total acid, diacetyl and polyphenols reached the national standard on beer physical-chemical requirement. After six months, the turbidity of beer was 0.483EBC, and the beer was still limpid.4. The safety of RCCM was studied, and the results showed that the contents of cerium in beer clarified by RCCM were lower than the contents of cerium in beer clarified by diatomite, and the glutaraldehyde was not detected. It proves that RCCM have no effect on beer safety. The regeneration of RCCM was studied and the effect was best when the regeneration reagent was hydrochloric acid with 3% concentration and NaOH with 4% concentration. The dosage of regeneration reagent was studied, and the results showed that the dosage of hydrochloric acid with 3% was 15 times the volume of RCCM, and the dosage of NaOH with 4% concentration was 20 times the volume of RCCM.This research optimized the process of beer clarification, improved the beer stability, guaranteed the safety of beer, and enhanced the ability of beer competition in the international market. RCCM prepared in this research provide a new filter medium for beer clarification and also provide a new way for utilization of chitosan resource.