Results and discussion
End product evaluation
Physical characteristics of crackers were measured to determine
the effect of supplementation of HSR on stack weight,
stack height, and specific volume Table 1. The stack weight,
stack height, and specific volume of crackers decreased as
the addition level of HSR increased. In other words, HSR containing
crackers were denser compared to the control samples.
The presence of gluten protein in wheat flour was presumed
responsible for the increased volume and height. Gluten develops
when wheat flour is mixed with water and it forms a matrix
that retains more gas. As the dough is baked, it expands more,
thereby increasing loaf volume and height. However, addition
of HSR to wheat flour lowered the amount of gluten in the
blends, causing poor gas retention and thus reduced loaf volume
and height of the blended crackers. The presence of relatively
large particle fibers in HSR might also have played
significant roles in reducing crackers volume by puncturing
gas cells as the dough was expanding. The results are in agreement
with findings by Wu et al. [15].
Moisture contents of crackers were assessed to determine
storability of the products. The results indicated that the moisture
contents among samples containing HSR were statistically
different from each other, and that HSR crackers had a significantly
lower amount of moisture compared to control samples.
The low moisture content of the products is important
for prolonging their shelf life. In addition, water content of
baked products is of interest in the degree of crunchiness as
well as stability of phenolic compounds. It has been suggested
that hydrolysis may have a role in phenolics degradation,
and cleavage of isoflavones esters to glucosides occurs via