Effects of fibre-rich rye milling fraction on the functional properties and nutritional quality of wholemeal rye bread

Abstract

The goal was to assess the effects of partial replacement of wholemeal rye flour with 30%, 40% and 50% of the high-fibre rye flour (HFRF) on nutritional quality and sensory and physicochemical characteristics of breads. The HFRF supplemented breads (SB30, SB40, SB50) were compared in their nutrients and energy contents, physicochemical and sensory properties, and in vitro digestibility to the control bread (CB). There were no significant differences in shape and volume of loaves, crusts and crumbs appearance, taste and smell of two supplemented breads (SB30 and SB40) and the CB. Compared to the CB, all supplemented breads contained significantly more soluble and insoluble fibre, arabinoxylan and beta-glucan, but less available saccharides, including rapidly available glucose. Bread with 40% HFRF (SB40) yielded both, improved nutritional quality and acceptable sensory characteristics comparable to the CB. An in vitro overall digestibility of the SB40 was lower than that of the CB but the losses of dietary fibre and its components after enzymatic digestion were comparable between both breads. In conclusion, rye bread supplemented with 40% of the HFRF had improved nutritional quality and acceptable sensory and physicochemical characteristics and could be considered as an option to commonly consumed wholemeal rye bread.