Influence of Whole Wheat Flour Substitution and Sugar Replacement with Natural Sweetener on Nutritional Composition and Glycaemic Properties of Multigrain Bread

Prevalence of diabetes mellitus (DM) is rising globally and largely due to dietary lifestyle changes and urbanization. The concept of glycaemic index (GI) as a dietary tool for the management of DM has been recommended by international health organizations. Whole-grain wheat flour (WWF), ‘acha’ flour (AF), and pigeon pea flour (PPF) were combined in different ratios (80:10:10, 70:15:15, 70:20:10, and 60:20:20) and 100% WWF served as control. Bread was produced from the flour blends using white sugar (sucrose) and/or date palm fruit sugar (DPFS) representing 50 or 100% sugar replacement. Physical attributes, nutritional composition, GIs, and consumer acceptability of the breads were evaluated using standard methods. The multigrain breads had lower values for height, volume, and specific volume, but were most dense than the control [WWF+sugar (WAPC)]. The protein, ash, and crude fibre contents of the breads were significantly improved compared with the control, especially breads containing 100% DPFS, whereas carbohydrate and energy contents were comparable. The breads also contained significant amounts of macro and micro elements and a Na/K ratio of less than 1. Phytate/mineral molar ratios of the bread were lower than the respective critical limits. Multigrain breads showed low GI, especially those with >20% whole wheat substitution and 100% DPFS compared with WAPC, with intermediate GI (65.61) and high glycaemic load (GL). WWF+AF+PPF+DPFS (60:20:20:100) exhibited the highest protein content, a significant fibre content, lowest carbohydrate, GI, GL, and postprandial blood glucose responses, thus may be a suitable dietary guide for sustained health.