Characterization of bread enriched with sprouted grains

A number of studies have shown that the nutritional and chemical profile is altered upon sprouting of cereal and non-cereal grains [1]. In the course of sprouting, starch is broken down to simpler sugars, in a way that depends on the process conditions. At the same time, sprouting affects the concentrations of some nutrients and anti-nutrients (such as phytic acid) [2], and results in the formation of products (and precursors) that may have an impact on the sensory properties of the product [3]. Optimum sprouting conditions need to be defined for individual grains in consideration of the desired product and of the grain being sprouted. The aim of this study was to investigate the overall quality of a sourdough bread enriched (≥5% w/w) with either sprouted buckwheat flour or sprouted wheat flour, in comparison with flours from non-sprouted grains. Addition of the flours from sprouted grains were expected to improve the product mostly from a sensory standpoint, as nutritional improvement at these enrichment levels may be considered marginal. However, even such a small enrichment can cause problems during the breadmaking process, that need to be carried out in a specific way. E-nose data indicate that bread containing significant amounts of flour from either sprouted grain had unique aroma components. Panelists gave indeed higher scores to the enriched breads. Image analysis of our model bread indicated no changes due to the addition of sprouted wheat. On the contrary, addition of non-sprouted buckwheat flour had detrimental effects on the appearance of wheat-based bread. These detrimental effects were absent when sprouted buckwheat was used. From a molecular standpoint, sprouting gave the expected starch breakdown. Proteins were also affected, but protein breakdown was minimal and limited to large proteins. As a consequence, proteolytic products did not interfere with protein-protein interactions crucial to the final quality of the bread. In conclusion, sprouting selectively breaks down biopolymers in grains. Careful conduct of the sprouting process may lead to the selective formation of breakdown products that contribute unique aroma notes upon bread baking, without having detrimental effects on the appearance of the product. References [1] Donkor ON, Stojanovska L, Ginn, P, Ashton J, Vasiljevic T (2012). Germinated grains – Sources of bioactive compounds. Food Chem. 135, 950–959. [2] Koehler P, Hartmann G, Wieser H, Rychlik M (2007). Changes of folates, dietary fiber, and proteins in wheat as affected by germination. J. Agric. Food Chem. 55, 4678-4683. [3] Singh H, Singh N, Kaur L, Saxena SK (2001) Effect of sprouting conditions on functional and dynamic rheologicalproperties of wheat. J. Food Eng. 47, 23-29.