Characteristics of In-Vitro Starch Digestibility in Wheat Bread with Arabinoxylans, Baked Using Sourdough or Postponed Baking Methods.

The aim of this study was to characterize in vitro digestion of wheat breads baked with sourdough or the postponed baking method without and with arabinoxylan (AX) of different molar mass. The influence of the AX share on the rate of starch digestion, the molar mass of resistant starch (RS) and the pasting characteristics of crumb suspensions of breads baked by the sourdough and postponed baking methods were investigated. Sourdough wheat breads were characterized by contents of very slowly digestible starch (DS) of 1.3% and RS of 1% higher in the crumb, compared to breads baked by the postponed baking method. In the crumb of sourdough breads, after storage for 1 and 3 days, in all variants of the samples (especially with the 2% share of high molar mass AXs), the content of the rapidly digested starch (RDS) fraction decreased, the content of the slowly digestible (SDS) and DS fractions did not change significantly, while the content of the RS fraction increased. In addition, the RS fraction present in the crumb of sourdough breads was generally characterized by a lower molar mass than the RS isolated from the crumb of breads baked by the postponed baking method. The crumb of wheat breads baked using sourdough was characterized by higher viscosity, compared to those baked by the postponed baking method.