Mutational inactivation of proteins involved in para-cresol production in certain milk products results in improved taste and odour. The undesirable para-cresol forms over time as a result of enzymes produced by the bacterium that produces gellan gum. Since the gellan is typically used in a relatively unpurified form, the enzymes are added to the milk along with the gellan. Inactivation of the enzymes is a genetic means of eliminating the enzymes without requiring any additional purification or processing.