fermentation of resistant dextrins was analyzed using
a quantitative equation (prebiotic index – PI). The PI
equation is based on the changes in key bacterial groups
during fermentation. The bacterial groups incorporated
into this PI equation were bifidobacteria, lactobacilli,
clostridia and bacteroides. The equation assumes that an
increase in the populations of bifidobacteria and/or lac- tobacilli is a positive effect while an increase in bacte- roides and clostridia is negative (Palframan et al., 2003).
The PI equation is described below:
PI = (Bifidobacterium/Total bacteria) — (Bacteroides/Total
bacteria) + (Lactobacillus/Total bacteria) – (Clostridium/Total
bacteria).
pH changes. Changes in pH were monitored with an
Elmetron CP-401 pH-meter (Elmetron, Poland)