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

Abstract

Zymomonas mobilis, because of its fermentative metabolism, has potential food applications in the development of leavened baked goods consumable by people with adverse responses to Saccharomyces cerevisiae. Since Z. mobilis is not able to utilize maltose present in flour, the effect of sucrose addition (2.5 g/100 g flour) on bread dough leavening properties was studied. For comparison purposes, leavening performances of S. cerevisiae with and without sucrose were also investigated. Doughs leavened by Z. mobilis without sucrose addition showed the lowest height development (14.95 ± 0.21 mm) and CO2 production (855 ± 136 mL). When sucrose was added, fermentative performances of Z. mobilis significantly (p < 0.05) improved (+80% and +85% of gas production and retention, respectively), with a dough maximum height 2.6 times higher, results indicating that Z. mobilis with sucrose can be leavened in shorter time with respect to the sample without addition. S. cerevisiae did not benefit the sucrose addition in terms of CO2 production and retention, even if lag leavening time was significantly (p < 0.05) shorter (about the half) and time of porosity appearance significantly (p < 0.05) longer (about 26%) with respect to S. cerevisiae alone. Results demonstrate that in the presence of sucrose, Z. mobilis can efficiently leaven a bread dough, thus providing innovation possibilities in the area of yeast-free leavened products.

Yeast-Free Doughs by Zymomonas mobilis: Evaluation of Technological and Fermentation Performances by Using a Metabolomic Approach

“…Musatti et al [7] reported that with a lower inoculum (7 vs. 8 log CFU/g dough used here) and in presence of sucrose, Z. mobilis DSM 424 showed a significantly higher lag time of 7.12 h; in the same condition, the benchmark yeast S. cerevisiae, evidenced a leavening rate of around 15 mm/h and a lag time of around 3 h.…”

“…Maltose, glucose and ethanol concentrations were determined through an HPLC system (L 7000, Merck Hitachi) equipped with refractive index detector [6]. Z. mobilis, Aerobic Mesophilic Count (AMC) and yeasts and moulds (Y&M) counts were carried out as previously stated [7] and reported in log colony forming units/g of dough (log CFU/g) as means and standard deviations values.…”

“…Nevertheless, results showed that a controlled addition of glucose to the dough generated better results than those obtained with the co-culture of L. sanfranciscensis, which strongly acidified the dough slowing down the growth of Z. mobilis. Recent results also evidenced that sucrose can be successfully used by Z. mobilis to leaven a dough, with improved gas production and retention capacity [7].…”

Characterization of Two Zymomonas mobilis Wild Strains and Analysis of Populations Dynamics during Their Leavening of Bread-like Doughs

“…Musatti et al [ 8 ] reported that Z. mobilis strains belonging to the official DSMZ collection (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH), grown on a medium without yeast–derived compounds, were able to efficiently leaven model doughs when glucose was added to boost the ED catabolic pathway (20 g flour, 15 mL distilled water and 2 g glucose, leavening at 29 °C). Its interesting leavening performance was also confirmed in bread-like dough formulations (333 g flour, 167 mL distilled water) added with glucose or fructose [ 9 , 10 ]. However, when employing these strains, the addition of NaCl was found to slow down the dough rising.…”

Metagenetic Analysis for Microbial Characterization of Focaccia Doughs Obtained by Using Two Different Starters: Traditional Baker’s Yeast and a Selected Leuconostoc citreum Strain

“…Similarly, there is an increasing interest of the market in “yeast-free” leavened foods, due to the recent concern about the role of S. cerevisiae (particularly its anti-antibodies) in several pathologies, including Crohn’s disease, gastro-esophageal reflux, acne inversa and gut fermentation syndrome [ 20 , 21 , 22 , 23 ]. In this context, processes to develop “yeast-free” bakery products have been formulated and applied at the industry level [ 24 , 25 , 26 ]. In particular, we developed a protocol based on the use of a liquid sourdough started with a single bacterial strain for “yeast-free” bread and focaccia production, obtaining products with improved functional/nutritional characteristics compared to those made with baker’s yeast [ 24 , 27 ].…”