Mathematical Model of Sugar Uptake in Fermenting Yeasted Dough

Abstract

Fermentation prior to freezing significantly reduces the shelf life of frozen dough, measured as a decline in proofing power. Changes during fermentation caused by yeast metabolism have previously been described empirically on a dough weight basis and have not been mathematically modeled. In this work, yeast metabolites were quantified in fermenting dough and their concentrations were estimated in the aqueous environment around yeast cells. The osmotic pressure in the aqueous phase increases by 23% during 3 h of fermentation, which depresses the freezing point by 1 degrees C. The rise in osmotic pressure and the accumulation of ethanol may affect phase equilibria in the dough, baking properties, and the shelf life of frozen dough. Predictive modeling equations fitted sugar concentration data accurately. It was found that the preference of baker's yeast for glucose over fructose was stronger in fermenting dough than in liquid fermentations. The usefulness of the model in industrial bakery formulation work was demonstrated.

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

“…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).…”

Physicochemical changes in a model protein bar during storage

“…A procedure described earlier (Loveday & Winger, 2007) was adapted. A 100 mL plastic container was removed from storage and approximately 30 g of protein bar material was gradually added to liquid nitrogen in an aluminum dish.…”

Simultaneous Extraction and Enzymatic Quantification of Glucose, Sucrose, and Ethanol in Fermenting Yeasted Dough

“…Ethanol constantly accumulated in the dough, reaching 29.3 ± 0.9 mmol/100 g of dough after 3 hr of fermentation. When glucose was measured using heated extracts, the decline in glucose reflected the accumulation of ethanol, as predicted from anaerobic fermentation biochemistry (Loveday and Winger 2007).…”

“…2). When glucose was measured using heated extracts, the decline in glucose reflected the accumulation of ethanol, as predicted from anaerobic fermentation biochemistry (Loveday and Winger 2007). 3).…”