TSS and TS did not alter significantly during storage (Fig. 2). The
TSS contents were always at 19
Brix, whereas those for TS were in
between 22.61 and 22.92 g/100 g. In contrast, significant changes in
titratable acidity and pH were observed (Fig. 3) and the two values
were inversely related to each other. The values for titratable
acidity changed from 1.00 g/100 g (day 1) to 1.14 g/100 g (day 21)
and those for pH from 4.31 (day 1) to 4.01 (day 21), respectively. As
the storage time is extended, the yoghurt cultures use lactose in
their heterofermentative activity and, in turn, produce mainly lactic
acid