3. Results and discussion
3.1. Hydration properties of flour-hydrocolloid blends
The hydration properties of all flours in the presence of diverse
hydrocolloids added at different levels (2% and 4%) are shown in
Table 1. In general, the hydrocolloids used in this study tended to
increase the hydration properties of three flours in a dose-dependent
manner, although some exceptions were detected in the low level
alginate groups.The effects of hydrocolloidsweremore noticeable on
wheatflour than onwholewheat andbuckwheatflours. In the case of
wheatflour, the hydrationparameterswere significantly increased in
the presence of three hydrocolloids in a dose-dependent manner
(p < 0.05). In contrast, the hydration properties of whole wheat and
buckwheat flourswere improved by adding xanthan gum(p < 0.05).
The addition of alginate induced a significant increase in water solubility
with the exception of buckwheat flour (p < 0.05). Inparticular,
xanthan gum exhibited a critical increase in the water absorption
index and swelling power of all flours (p < 0.05). The carboxyl and
hydroxyl groups in the structures of hydrocolloids allow them to
readily bindwater, resulting in the increasedswelling ability of starch
granules (Lee et al., 2008; Mandala & Bayas, 2004; Rojas, Rosell, &
Benedito de Barber, 1999). Although the improvement in the hydration
property was caused by the structural properties of hydrocolloids
with high affinities for water, the amount of hydration was
greatly dependent on the type and level of hydrocolloid and the
nature of flour or starch (Gularte & Rosell, 2011).