APPLICATION OF NEURAL NETWORKS FOR CONTROLLING AND PREDICTING QUALITYPARAMETERS IN BEER FERMENTATION

The biochemical pathways involved in the production of ethyl caproate, a secondary product of the beer fermentation process, are not well es tablished. Hence, there are no phenomenological models available to co ntrol and predict the production of this particular compound as with o ther related products. In this work, neural networks have been used to fit experimental results with constant and variable pH, giving a good fit of laboratory and industrial scale data. The results at constant pH were also used to predict results at variable pH. Finally, the appl ication of neural networks obtained from laboratory experiments gave e xcellent predictions of results in industrial breweries and so could b e used in the control of industrial operations. The input pattern to t he neural network included the accumulated fermentation time, cell dry weight, consumption of sugars and aminoacids and, in some cases, the pH. The output from the neural network was an estimation of quantity o f the ethyl caproate ester.