Influence of starter and nonstarter lactic acid bacteria on medium redox

Cheddar and other bacterial-ripened cheeses commonly contain high numbers of nonstarter lactic acid bacteria (NSLAB) that enter cheese through processing equipment or milk. Although NSLAB can have a significant effect on flavour development, little is known about the factors that influence the growth and composition of the nonstarter biota in cheese. Thus, the complexity and number of NSLAB in cheese, and their effect on cheese quality, is largely a matter of chance. One factor that may affect the NSLAB population dynamics is oxidation-reduction potential (E-h). This paper examines the relationship between starter or NSLAB growth and medium E-h in a laboratory-scale bioreactor.