Bioavailability of starch in bread products. Postprandial glucose and insulin responses in healthy subjects and in vitro resistant starch content.

Attempts to reduce glycaemia to bread were evaluated in healthy subjects. The contents of in vitro resistant starch (RS) were also measured in the bread products. The potential of including intact barley kernels at different concentrations (80% and 40%) was tested in two products (SCB-80 and SCB-40). Three variants of barley bread made from wholemeal were also studied: ordinary (WMB), sourdough fermented (WMB-s) and one made from scalded flour (SWMB). A commercial pumpernickel bread (PB) based on sourdough fermented rye kernels was included for comparison and a white wheat bread (WWB) used as reference for calculation of glycaemic index. The glycaemic and insulinaemic indices for SCB-80 were 33 and 39, and for PB 69 and 61, respectively. The glycaemic index was lowered also in case of SCB-40 (66). No differences in indices were found between the WMB products or versus WWB. A high content of RS (8% starch basis) was found in the PB product, compared with the remaining bread products (0.8-1.7%).