The evaluation of sucrose replacement by polydextrose in pound
cakes and the impact on the product quality were evaluated. Rheological
tests for analyzing the structural changes during shear stress as
well as the texture parameters like firmness and adhesive force of
batter were measured.
Polydextrose containing batters was more susceptible to shear
stress than sucrose containing batters. A maximum content of polydextrose
in batter increased the firmness of the batter by 13% when
compared to sucrose containing batter. This can be explained by the
higher molecular weight, water absorption and solubility of the polydextrose.
In view of the results of the batter stiffness during the
micro-baking-test polydextrose showed no significant differences
when compared to the sucrose. The main result of the study is the dependency
between physical batter expansion and end product volume,
supported by a high significant correlation between specific
volume of the batter and pound cake. Results of the physical measurements
characterizing the baked pound cakes showed similar tendencies
for both particular components. Additionally polydextrose
containing cakes showed similar behavior when compared to the
control products containing sucrose when stored up to 18 days. As already
mentioned the most important characteristics are the typical
high volume and soft texture of pound cakes. Especially for these
two characteristics a polydextrose content of around 40% is enough
to get the same specific cake volume and crumb firmness like pound cakes produced by 100% sucrose (in the range of standard deviation)
(Table 2(A)).
In conclusion, the usage of polydextrose allows a total sucrose replacement
preserving the typical soft textural and specific volume of
pound cakes. These results offer the possibility to produce a pound
cake using rebaudioside A (Reb A) as a natural sweetener, this lead
to a significant reduction of calories (~10%).
Reb A is one of the major components of Stevia rebaudiana (Bertoni).
The sweetness of Reb A is 200–300 times higher than sucrose and has a
clean taste and when used in pound cake it does not affect the quality of
the cakes . In addition to the impact of the
quality characteristics of pound cake, this study provides an insight in
the foam formation and stability of pound cake systems.