A suitable model of microbial survival curves for beer pasteurization

Published isothermal inactivation data indicated that beer can undergo under- or over-processing depending on the target log reduction and the shape of the survival curve of a microorganism if traditional first-order model is used. This was demonstrated for a mold, yeasts and lactic acid bacteria by use of a more flexible and convenient model than the first-order model, namely Weibull model. The parameters of the Weibull model can be reduced from two to one with a very a slight loss of goodness-of-fit. The validity of the proposed model should also be checked for mixed populations of microorganisms in beer and non-isothermal treatments for beer. Beer can be the first product to validate the proposed model in industrial base since it has been free from problems with pathogenic microorganisms. If the model provides the requirements then it can also be used in other food products. This will minimize the energy expenditure for pasteurization and provide minimal processing to achieve a better food quality. (C) 2006 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.