Bread Dough and Baker's Yeast: An Uplifting Synergy

Abstract

Yeast-mediated dough fermentation is an important phase in the bread making process. The fermentative performance of yeast cells during fermentation is of critical importance for final bread quality, since yeast cells produce CO 2 and other metabolites that have an influence on dough rheology and bread texture, volume, and taste. Different factors affect the fermentative performance of yeast cells during dough fermentation, including dough ingredients, fermentation conditions, the type of yeast strain used and yeast pregrowth conditions. Bread dough is a complex matrix that contains several ingredients that can affect the fermentation rate of yeast cells. Although the individual effects of sugar availability and salt level on the leavening ability of yeast have been studied extensively, a comprehensive overview of the relationship between bread dough constituents, fermentation conditions and yeast functionality is still lacking. Moreover, the dough environment is highly variable as several types of dough like lean, sweet or frozen doughs are currently produced by commercial bread producers. For optimal fermentation rates in different types of dough, the use of appropriate yeast strains with specific phenotypic traits is required. Therefore, many researchers have focused on the improvement of yeast strains for optimal fermentation in different types of dough like lean, sweet or frozen dough. Against this background, this review summarizes the current knowledge on the interaction between bread dough and baker's yeast and how to improve this interaction, thereby providing a useful background for further research concerning the functionality of yeast in bread dough.

Zymomonas mobilis in Bread Dough: Characterization of Dough Leavening Performance in Presence of Sucrose

“…Such a behavior highlighted that the presence of sucrose produces an osmotic stress able to inhibit S. cerevisiae metabolism. Note that S. cerevisiae consumed sucrose more rapidly than Z. mobilis because of the presence of invertase [26,27]. In Z. mobilis, sucrose can be split extracellularly or intracellularly but also levan can be produced via levansucrase [14].…”

The time-dependent rheology of fermenting wheat flour dough: effects of salt and sugar

“…A substantial amount of sucrose (6 wt% or more) is often included in the dough recipe as a supplementary nutrient source for the yeast cells and to improve bread flavour (Myers et al, 1998;Struyf et al, 2017). To investigate the impact of changes in the sugar content on the rheological behaviour of dough and the fermentation process, doughs were prepared with or without additional sucrose and subsequently tested both in the unfermented and the fermenting state.…”

“…However, without additional sucrose the yeast quickly runs out of readily fermentable sugars, and is forced to switch to the fermentation of maltose. During this readjustment, the gas production is likely to decline (Loveday and Winger, 2007;Struyf et al, 2017). In addition, during fermentation yeast produces small amounts of glycerol, which tend to accumulate inside the yeast cells and so protect them against the low extracellular water activity created by sugar and/or salt (Nevoigt and Stahl, 1997).…”

Baker's Yeast Catalyzed Multicomponent Reactions: A New Hope?

“…Wild type BY ( Saccharomyces exiguous) is found in many plants, grains and fruits. Historically, BY was first used in ancient Egypt to ferment sugar in bread dough and thereafter, it became a household and commercial substrate for food processing (Figure ) . Typically, the fermentation process produces carbon monoxide and ethanol.…”