A general method to predict pH and lactic acid dissociation during fermentation processes

Abstract During food fermentation processing, the biochemical activity of microbial starter cultures is exploited to obtain a product with optimal sensorial quality, stability and safety. This activity principally involves the production of lactic acid. To develop a suitable mathematical model of the fermentation process, the typicaltime-dependent profile of pH and undissociated lactic acid should be incorporated. This contribution introduces a novel, robust computation method for the acidifying behaviour of lactic acid in a complex growth medium. In combination with a model from literature for microbial growth and lactic acid production, the method is successfully appliedto experimental data of Lactococcus lactis SL05.