The effect of PP and BBP fibers addition on the alveograph
characteristics of wheat flour dough was shown in Table 2. PP and
BBP fibers addition showed a significant effect on alveograph parameters
of fortified samples and control dough. Dough resistance
to deformation or tenacity is a predictor of the ability of dough to
retain gas. The highest effect was exhibited by fiber added at 1 g/
100 g ratio. This is likely due to the interactions between polysaccharides
and proteins from wheat flour as previously reported
by Jones and Erlander (1967). Likewise, the extensibility of dough
(L), an indicator of the handling characteristics of the dough, was
greatly reduced by fibers addition. The resulting effect on P and L
values becomes evident in the P/L ratio. The addition of PP and BBP
fibers at 1 g/100 g level led to the highest P/L ratio (1.13 and 1.42
from PP and BBP fiber, respectively versus 0.73 in the control). This
might be caused by the high content of cellulose present in fiber,
which promotes a strong interaction between fiber and flour protein
(Wang, Rosell, & Barber. 2002). The deformation energy (W)
was increased by the addition of PP and BBP fibers and the highest
valuewas detected at the level of 1 g/100 g (18.8 and 20.8 mJ for the
fiber from PP and BBP, respectively vs 18.8 mJ in the wheat flour).
Our findings are in line with the observations realized by Sudha
et al. (2007a) and Anil (2007) who reported a decrease on elasticity
and an increase on resistance to extension of dough prepared by
incorporating apple pomace and hazelta tested as sources of dietary
fiber, respectively.