Rheological and sensory behaviour of rice flour dough: effect of selected additives in relation to dough flattening.

The handling of rice flour doughs in terms of sheeting,
flattening and rolling is difficult due to the absence of
gluten forming proteins; scope exists to improve these characteristics
by incorporating appropriate additives during the
preparation of rice doughs. Different levels of additives such
as whey protein concentrate (WPC) (0–10 %), xanthan gum
(0–5 %), sucrose (0–20 %) and salt (0–2 %) have been
incorporated, and the rheological (small-deformation
oscillation) as well as sensory characteristics have been determined,
in addition to microstructural observations and finding
inter-relationships. The second order polynomial can adequately
explain the rheological parameters like storage modulus,
loss modulus and complex viscosity (R=0.863–0.889,
p≤0.01) while it is poor for phase angle (R=0.659, p≤0.01).
Among these additives, xanthan gum imparts the strongest
effect (significant at p≤0.01) followed by whey protein concentrate.
The effects of these additives are predominantly
linear though quadratic effects are also significant in several
cases. A cohesive microstructure with improved binding occurs
with a high level (7.5 %) of WPC. It is concluded that a
judicious selection of additives in appropriate levels can develop
rice doughs that possess the desirable handling properties
leading to preparation of products.