Evaluation of the functionality of five different soybean proteins in yeast-leavened pan breads

Soybean (SB) products are a source of proteins that complement the amino acid profile of cereal-based products and consequently improve human health. Four different SB flours (SBF-1 to SBF-4) and a SB concentrate (SBC) were incorporated into refined wheat flour in order to increase approximately 20-25% the protein content. The composite flours were processed into yeast-leavened pan breads. The SB fortified breads were characterized in terms of dough rheological, baking performance, bread crumb texture and color and sensory properties. The different SB proteins affected differently rheological properties of doughs, bread properties and quality. Addition of the SB proteins increased more than 3% optimum dough water absorption and consequently bread yield but decreased between 7 and 13% bread volume. The fortified breads also had a darker crumb. The best SB protein sources were SBF-3 and SBC which had respectively 75.5 and 52% PDI, 24 and 36% NSI, 4.0 and 8.3 water absorption and 50.3 and 36.9% water solubility indexes. These SB-fortified breads averaged 23% more protein and almost twice as much lysine compared to the control. Therefore, these SB proteins can be utilized to produce yeast-leavened breads with higher protein and upgraded protein quality. (C) 2015 Elsevier Ltd. All rights reserved.