In the absence of a starter culture Salmonella Typhimurium DT104 increased in counts
until 12 h, but the counts started to fall off gradually, although complete elimination was
not observed (Figure 2). In the presence of pure or mixed starter cultures, however, an
initial increase was noted in counts of test strain until 12 h, only to be followed by a sharp
fall in count and complete elimination at 48 to 72 h. Rate of elimination was notably
faster when the starter flora consisted of a mixed culture of LAB followed by
lactobacillus starter alone and Pediococcus starter alone. The pH of fermenting mash
decreased sharply until 12 h in all cases (Figure 2). The low pH was maintained until
48 h. The pH increased sharply after 48 h. However, Lb. plantarum1 maintained the low
pH until 120 h.
The counts of E. coli ATCC 25922 increased until 12 h both in presence and absence
of a starter culture (Figure 3). There was a general trend of decreasing count in both cases
thereafter. E. coli survived much longer in the absence of starter culture but disappeared
at 144 h. Faster elimination of the test strain was noticed in the presence of mixed
starters. No marked difference was noticed between the pure starter cultures on E. coli
elimination. There was a steady fall in pH of the fermenting mass containing E. coli
ATCC 25922 until 48 h even in the absence of starter culture (Figure 3). However, the
pH rose sharply after 48 h in the absence of starter culture. Among the starter cultures,Changes in counts of (a) S. Typhimurium DT104 and (b) pH during wakalim
fermentation in the absence of starter culture (♦), and when co-cultured with pure
culture of Lb. plantarum1 (■), Ped. Pentosaceus1 (▲) and mixed culture of
Lb. plantarum1 and Ped. Pentosaceus1 (×)