Preparation and characterisation of novel, dual-modified potato starches and their performance in baked products

Dual modification of potato starch in one step by combining annealing with ion exchange was identified as a potent strategy to influence functional starch properties. This dual modification was upscaled for food application studies and performed for both native and waxy potato starch at optimized conditions (55 °C for 24 h in MgCl2 as well as in KCl solution). Annealing resulted in higher gelatinization temperatures by ca. 5.0 °C in native and ca. 7.6 °C in waxy potato starches (differential scanning calorimetry) and higher relative crystallinities (X-ray powder diffraction). Further fine-tuning of pasting properties of annealed starches was readily achieved by ion exchange of cations bound to phosphate ester groups. Here, divalent cations cause ionic crosslinking, lowering peak viscosities. Baking trials comprised preparation of breads, where 20% of wheat flour was replaced by our physically modified starches and vital gluten was added, as well as pound cakes, where wheat starch was replaced. Breads containing native and dual-modified starches were slightly smaller (10–15%) and denser (23–27%) than the reference bread. Only small differences in specific volume and hardness when fresh or after storage were observed in pound cake samples. With this, dual-modified starch were successfully applied in bread and cake, adding to the very limited studies on annealed starches in baked products.