Estimation of the ester formation during beer fermentation using neural networks

Most of ester compounds found in beer are produced by yeast during fermentation. They contribute significantly to beer flavour. Therefore, the control of their formation is very important to maintain consistent quality of the product. In this article, the influences of fermentation temperature and dissolved oxygen content in the production of ethyl acetate and isoamyl acetate were analysed using a comparative studied between kinetic methods and neural networks. The results confirmed that the production of ester and isoamyl acetate can be expressed as a function of the ethanol formation, however the isoamyl acetate production is independent of the temperature of the fermenter. The neural networks allowed obtaining a good prediction of ester's production without to use complex model (kinetic analysis). (C) 2007 Elsevier Ltd. All rights reserved.