Glycaemic response to frozen stored wholemeal-flour rolls enriched with fresh sourdough and whey proteins

The aim of this study was to examine the effect of addition of fresh sourdough and whey proteins to partially baked and frozen wholemeal wheat-flour rolls on the glycaemic index (GI). The study was performed on healthy humans (n = 15). Each human tested five types of wholemeal wheat rolls: (1) fully baked, non-frozen (FBNF), (2) partially baked and frozen (PBF), (3) fully baked, non- frozen with the addition of fresh sourdough (FBNF + FS), (4) partially baked and frozen with the addition of fresh sourdough (PBF + FS), and (5) partially baked and frozen with the addition of fresh sourdough and whey proteins (PBF + FS + WP). The results of the study show that supplementing whole-wheat rolls with sourdough, or freezing separately and supplementing with sourdough and whey proteins combined with frozen storage, significantly reduced the glycaemic response.