Study On The Characteristic Of Carrageenan And Its Influence On Beer Brewing

The characteristic of different types of carrageenan was investigated in this paper. The large-scale experiment was done in the brewing with carrageenan as additive. The theoretical evidence was provided for the carrageenan using in the brewery. It was found that the viscosity of carrageenan was different depending on the alga variety, process method and type in the research. The higher the pH value was, the higher viscosity of carrageenan was. In the common situation, the viscosity of type λ carrageenan was the highest, and the viscosity of type κ carregeenan was the lowest. There was the negative relationship between the carrageenan viscosity with the temperature, the double-screw structure would be enlaced and formed by carrageenan from the irregular loop structure, and then the reticular structure would be formed with the temperature decreasing. The gelatin would be produced while the type κ or typle ι carrageenan was coolded. So it was found that the carrageenan molecular weight will be changed by the temperature, pH value and mass proporation. The beer filtering speed would be improved and the nitrogen content which could be sedimented during wort boiling would be decreased when the carrageenan was added in the boiling tank. The reaction principle between the carrageenan with protein might be the electric charge neutralization or bridge function. The reticulation structure which the carrageenan had could be combined with several protein particle to be precipitation.The precipitation effect with ATC was better than ATS, but the reaction speed with ATS was faster than ATC; there was better effect when the ATC and ATS was used together than by alone; the proportion was 90:10, reaction time was 4~5h, the adding volme was 20mg/L.The precipitation effect of carrageenan will be affected by the type and concentration of ion of wort. There was negative effect with high K+ and Ca2+ concentration, the precipitation speed would be slowered, the wort turbidity would be increased; while there was positive effect with Na+ and Mg2+ concentration, the precipitation speed would be enhanced.In large-scale experiment, the wort turbidity was decreased obviously, while the other index was not influenced while the carrageenan was added in the wort boiling. The yeast flocculation would not be affected, but the fermentation speed was faster than before. The diacetyle reduced time was shortened for about 1-2 days. At the same time, the wort loss was decreased. The bright beer turbidity was decreased by 30%, filtering speed was increased 37.8%, kieselgur consumption per tonnon beer was decreased by 50.0% and the foam quality was not influenced. The beer shelf life was prolonged and the beer non-biological stability was improved. The cost was much lower than the other additive such as slilica xerogel and tannin.