This equation was originally developed in the 19thcentury to describe
mortality as a function of age and is used for actuarial purposes, but was
found to give a good fit to microbial growth data. More recently the
Baranyi equation has found favour and, although considerably more
complex, has the advantage of having been developed specifically to
describe microbial growth in foods. Once a large number of such values
Figure 3.16 Response surface plot describing the combined effect of temperature and pH
on the time for a 2 log 10 cycle growth increase ofYersinia enterocolitica. (a)
Acetic acid and (b) lactic acid
(C. Little)
Chapter 3 57