Starch–gluten interactions during gelatinization and its functionality in dough like model systems

• Investigation of heat-induced macrostructural behavior of starch–gluten model doughs.
• Application of realistic starch–gluten ratios and dough adapted water additions.
• Delayed gelatinization onset and decreased intensity by increased gluten content.
• Delayed gelatinization onset due to a barrier effect of gluten around starch granules.
• Decreased gelatinization intensity by a competitive hydration of gluten and starch.

Gluten–starch interactions are of specific importance during processing of cereal-based products. They become especially relevant during heating because of heat-induced changes within these biopolymers. A comprehensive characterization of the interactions during heating of the starch–gluten model dough based on its mechanical behavior taking into account its raw material ratios and dough adapted water additions has yet to be achieved. Thus, the macrostructural characteristics with varying starch–gluten ratios (92:8, 89:11, 86:14, 83:17, 80:20) in combination with different water additions (57.77, 60.78, 63.78, 65.58, 69.11 g water 100 g−1 blend) was analyzed in dynamic oscillatory study during heating from 30 to 98 °C. The delayed gelatinization onset (+7 °C) with increasing gluten content could be referred to a barrier effect of gluten around the starch granules with a hindered diffusion of water into the granules, since a competitive hydration was not significantly detectable. The decreased gelatinization intensity (−67%) due to an increased gluten content showed a negligible effect of the barrier effect and a more competitive hydration between gluten and starch. A further reason can be weakening zones in the leached amylose network and a hindered granule–granule interaction. Moreover, a simple possibility to identify the gelatinization onset in oscillatory tests by the derivative of the loss factor was defined.

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