Cookies containing GBR showed lower spread factors than those
prepared with brown rice flour, but the increase in GBR content in
cookies did not change the spread factor (Table 2). As discussed
earlier, enzymatic degradation occurred for the macromolecules
such as starch and protein in flours to the smaller sugars and
peptides (Palmiano & Juliano, 1972). The degradation of macromolecules
usually increases hydrophilic nature of the cookies as
found in the results of moisture content. Hoojjat and Zabik (1984)
reported that the cookie spread factor decreased by increasing
the amount of hydrophilic additives in cookie dough. Itwas because
that those hydrophilic small molecules had the capacity for
competing for freewater in cookie dough. In general, the freewater
which is limited in cookie dough plays a critical role in determining
the spread rate. When more free water exists, the internal dough
viscosity becomes lower and thus the spread factor of the baked
cookies increased. The cookies containing GBR thus showed the
lower spread factors than those containing brown rice flours.
Although the dough viscosity was not compared, the dough
containing GBR flours was much stickier than that containing
brown rice (data not shown).