Improvement of whole wheat dough and bread properties by emulsifiers

Authors: TEBBEN, LAUREN - Kansas State University; CHEN, GENGJUN - Kansas State University; Tilley, Michael - Mike; LI, YONGHUI - Kansas State University

Submitted to: Grain & Oil Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/16/2022
Publication Date: 6/22/2022
Citation: Tebben, L., Chen, G., Tilley, M., Li, Y. 2022. Improvement of whole wheat dough and bread properties by emulsifiers. Grain & Oil Science and Technology. 5:59-69. https://doi.org/10.1016/j.gaost.2022.05.001.
DOI: https://doi.org/10.1016/j.gaost.2022.05.001

Interpretive Summary: Emulsifiers are a group of compounds also known as surface active agents, or surfactants that are used in the baking industry to improve dough handling, increase loaf volume, and improve the crumb and textural properties of bread. Whole wheat bread has a smaller loaf volume and harder texture than white bread, so it is expected to benefit from the dough-strengthening and crumb-softening effects of emulsifiers. The objective of this research was to determine the effects of five different emulsifiers on whole wheat dough and bread properties, with a focus on loaf volume, bread texture, and staling. Emulsifiers (diacetyl tartaric acid esters of mono- and diglycerides (DATEM), polysorbate 80, sodium stearoyl lactylate (SSL), soy lecithin, and sucrose esters) were added individually to whole wheat flour at 0.2, 0.5, and 1.0% (flour weight basis). Overall results of dough tests showed that the emulsifiers exhibited dough-strengthening activity, though none of the emulsifiers significantly increased loaf volume compared to the control. However, the effects of emulsifiers on dough and bread are varied with differences in the flour, dough recipe, and production method. All of the emulsifiers reduced the rate of bread staling over 1 week, with the most effective treatments being 1% of either sucrose esters or polysorbate 80. The mechanisms behind the anti-staling activities of these emulsifiers in whole wheat bread has yet to be completely understood. Future work may examine the proposed interactions with starch and gluten, and how those influence bread staling. Furthermore, the interactions between emulsifiers and the components of wheat bran and germ should be investigated, in order to explain the differences in effects on whole wheat dough and bread compared to reported results in dough and bread made from refined flour.

Technical Abstract: Emulsifiers are used in the baking industry to improve dough handling, increase loaf volume, and improve the crumb and textural properties of bread. Whole wheat bread has a smaller loaf volume and harder texture than white bread, so it is expected to benefit from the dough-strengthening and crumb-softening effects of emulsifiers. The objective of this research was to determine the effects of five different emulsifiers on whole wheat dough and bread properties, with a focus on loaf volume, bread texture, and staling. Emulsifiers (diacetyl tartaric acid esters of mono- and diglycerides (DATEM), polysorbate 80, sodium stearoyl lactylate (SSL), soy lecithin, and sucrose esters) were added individually to whole wheat flour at 0.2, 0.5, and 1.0% (flour weight basis). Dough rheology and texture were determined by farinograph, mixograph, Chen-Hoseney stickiness test, and Kieffer rig uniaxial extensibility. Bread was prepared following AACC method 10-10.03 with some modification, and specific volume was determined. Moisture content and TPA were measured after 1, 3, and 7 days of storage at 22 °C. Crumb structure was measured by C-cell image analysis on Day 1. Differential scanning calorimetry (DSC) was used to measure starch changes after the 7 days. SSL increased dough stability, but sucrose esters and polysorbate 80 decreased this parameter. Sucrose esters, polysorbate 80, and SSL led to small but significant decreases in dough stickiness. DATEM, sucrose esters, and SSL increased the resistance to extension, whereas soy lecithin and polysorbate 80 increased dough extensibility. Soy lecithin and polysorbate 80 were the only emulsifiers that significantly increased loaf volume compared to the control. It appears that the dough-strengthening effect from some emulsifiers was not beneficial to the loaf volume of whole wheat bread. An increase in amylopectin retrogradation was observed for some treatments but was not related to an increase in crumb hardness. Adding higher levels of sucrose esters, polysorbate 80, and SSL (e.g., 1%) increased the formation of amylose-lipid complex during storage, and these formulations also produced the lowest crumb hardness on Day 7 and decreased the rate of crumb firming.