Flavour development in cheese is affected by the integrity of Lactococcus lactis cells. Disintegrated cells
enhance for instance the enzymatic degradation of casein to free amino acids, while integer cells are
needed to produce specific flavour compounds from amino acids. The impact of the cellular activity of
these integer cells on flavour production remains to be elucidated. In this study we investigated whether
lactose-deprived L. lactis cells that use arginine as an alternative energy source can extend cellular
activity and produce more specific flavours. In cheese experiments we demonstrated that arginine
metabolising cells survived about 3 times longer than non-arginine metabolising cells, which suggests
prolonged cellular activity. Cellular activity and flavour production of L. lactis was further studied in vitro
to enable controlled arginine supplementation. Comparable with the results found in cheese, the survival
rates of in vitro incubated cells improved when arginine was metabolised. Furthermore, elongated
cellular activity was reflected in 3e4-fold increased activity of flavour generating enzymes. The observed
prolonged cellular activity resulted in about 2-fold higher concentrations of typical Gouda cheese
flavours. These findings provide new leads for composing starter cultures that will produce specific
flavour compounds.