Beer fermentation process is a complex biochemical reaction process.It is the most important to control temperature of the wort in fermentation tank in accordance with the beer fermentation temperature curve so as to ...Beer fermentation process is a complex biochemical reaction process.It is the most important to control temperature of the wort in fermentation tank in accordance with the beer fermentation temperature curve so as to ensure the completion of fermentation.The controlled object is characterized by large inertia,long time delay and mutual coupling of three temperature areas.Based on this,a temperature control method for beer fermentation system is designed.Using digital incremental proportion integration differentiation （PID） control algorithm,the controlled quantity is transmitted to the controlled object after diagonal matrix decoupling.This simulation system can be completed in laboratory using VB and Kingview software,so it has the features of good security and low cost.It is very suitable for experimental teaching.展开更多
Beer fermentation is a dynamic process that must be guided along a temperature profile to obtain the desired results. Ant colony system algorithm was applied to optimize the kinetic model of this process. During a fix...Beer fermentation is a dynamic process that must be guided along a temperature profile to obtain the desired results. Ant colony system algorithm was applied to optimize the kinetic model of this process. During a fixed period of fermentation time, a series of different temperature profiles of the mixture were constructed. An optimal one was chosen at last. Optimal temperature profile maximized the final ethanol production and minimized the byproducts concentration and spoilage risk. The satisfactory results obtained did not require much computation effort.展开更多
Premature yeast flocculation(PYF)during beer fermentation is an undesired event by which yeast flocculate too early and heavily before the wort nutrition is exhausted.While PYF can be a major financial detriment to br...Premature yeast flocculation(PYF)during beer fermentation is an undesired event by which yeast flocculate too early and heavily before the wort nutrition is exhausted.While PYF can be a major financial detriment to brewers,the conditions that trigger it and the chemical composition of PYF are poorly understood.Gas chromatography-mass spectrometry results from this study indicated that purified malt PYF factor consisted of numerous polysaccharides;however,no protein was identi-fied.High concentrations of PYF promoted further yeast flocculation,which in turn decreased the rate of fermentation and increased acetaldehyde content of the beer.PYF factors were found to be derived primarily from malt husks and factors such as microbial content of the water used for germination,mixing malts with different PYF values,and presence of tannic acid were all found to influence the rate of yeast flocculation.Findings from this study may be beneficial in developing PYF prevention and control measures that can be applied to future brewing strategies.展开更多
基金Shandong Province Department of Education Science and Technology Program(No.J05C11)
文摘Beer fermentation process is a complex biochemical reaction process.It is the most important to control temperature of the wort in fermentation tank in accordance with the beer fermentation temperature curve so as to ensure the completion of fermentation.The controlled object is characterized by large inertia,long time delay and mutual coupling of three temperature areas.Based on this,a temperature control method for beer fermentation system is designed.Using digital incremental proportion integration differentiation （PID） control algorithm,the controlled quantity is transmitted to the controlled object after diagonal matrix decoupling.This simulation system can be completed in laboratory using VB and Kingview software,so it has the features of good security and low cost.It is very suitable for experimental teaching.
文摘Beer fermentation is a dynamic process that must be guided along a temperature profile to obtain the desired results. Ant colony system algorithm was applied to optimize the kinetic model of this process. During a fixed period of fermentation time, a series of different temperature profiles of the mixture were constructed. An optimal one was chosen at last. Optimal temperature profile maximized the final ethanol production and minimized the byproducts concentration and spoilage risk. The satisfactory results obtained did not require much computation effort.
文摘Premature yeast flocculation(PYF)during beer fermentation is an undesired event by which yeast flocculate too early and heavily before the wort nutrition is exhausted.While PYF can be a major financial detriment to brewers,the conditions that trigger it and the chemical composition of PYF are poorly understood.Gas chromatography-mass spectrometry results from this study indicated that purified malt PYF factor consisted of numerous polysaccharides;however,no protein was identi-fied.High concentrations of PYF promoted further yeast flocculation,which in turn decreased the rate of fermentation and increased acetaldehyde content of the beer.PYF factors were found to be derived primarily from malt husks and factors such as microbial content of the water used for germination,mixing malts with different PYF values,and presence of tannic acid were all found to influence the rate of yeast flocculation.Findings from this study may be beneficial in developing PYF prevention and control measures that can be applied to future brewing strategies.
