Defined co‐cultures of yeast and bacteria modify the aroma, crumb and sensory properties of bread

Abstract

Aims: Yeast and bacterial communities inhabit a sourdough starter to make artisanal bread. This study shows whether the interactions of micro-organisms derived from Australian sourdough starters provide some of the positive flavour, and aroma properties to bread by using defined sourdough cultures as the sole leaven in bread production. Methods and Results: An investigation of Australian sourdough starters found that they contained Saccharomyces cerevisiae and Kazachstania exigua yeasts. When these yeasts were inoculated alone to ferment wheat flour in an extended fermentation, the bread had a heterogeneous crumb structure, a deeper colour and a distinctive chemical aroma profile than those made with commercial baker's yeast. When bread was made combining these yeasts individually and in combinations with lactic acid bacteria also isolated from these sourdough starters, including Lactobacillus plantarum, L. brevis, L. rossiae, L. casei, the bread aroma profiles and crumb structure were more distinctive, with compounds associated with sour aromas produced, and preferred by sensory panels. Conclusions: The use of defined mixed cultures as the leaven in bread making, by exploiting the microbial diversity of artisanal Australian starters, can produce bread with distinctive and attractive aromas. Significance and Impact of the Study: Understanding and identifying the community ecosystems found in sourdough cultures and using them as the sole leaven in bread production provide novel insights into microbial interactions and how they affect food quality by removing the effects of commercial yeast strains.

Metabolism Characteristics of Lactic Acid Bacteria and the Expanding Applications in Food Industry

“…In fermented sourdough, lactic acid bacteria also play a role in the formation of flavor substances. For example, during the fermentation of bread sourdough, the combined use of lactic acid bacteria ( Lactiplantibacillus plantarum , Lactiplantibacillus plantarum, Furfurilactobacillus rossiae , and Lacticaseibacillus casei ) and yeast produces compounds related to the sour aromas of bread, and contributes to the aroma characteristics of bread ( Winters et al, 2019 ). Lactiplantibacillus plantarum may promote the production of more C 4 -C 6 alcohols in sourdough ( Liu et al, 2020 ).…”

Exploitation of Lactic Acid Bacteria and Baker’s Yeast as Single or Multiple Starter Cultures of Wheat Flour Dough Enriched with Soy Flour

“…Sourdough used in the food industry, is a traditional leaven agent, for the fermentation of dough with microorganisms like yeasts and lactic acid bacteria (LAB) [1,2]. The use of sourdough fermentation in bread leavening is gaining increased attention as it is recognized as a healthy and natural way of bread making [3].…”

“…According to recent studies, there are reciprocally stimulating interactions between LAB and Sc. Yeasts are a crucial element in foodstuff and beverage production [2], and are predominantly in charge of dough leavening [39].…”

Investigating effective variables to produce desirable aroma in sourdough using e‐nose and sensory panel

“…Sourdough is one of the important components in bread formulation as it directly affects the texture and flavor of the bread (Katina, 2005). Therefore, studying sensory properties using different flours and strains has been the subject of intense research (Lhomme et al., 2015; Mariotti et al., 2014; Salehifar & Shahedi, 2007; Sandvik et al., 2016; Torbica et al., 2010; Winters et al., 2019). In this study, the most common flours and microbial strains in sourdough production were used and extensive sensory screening was performed.…”

“…Glycolysis of pyruvic acid and Ehrlich pathway are the main mechanisms for producing the volatile compounds during fermentation in LAB and yeast strains, respectively (Pico et al., 2015). In the complex ecosystem of sourdough, different factors, including yeast and LAB species, flour type, consistency of dough (dough yield), time, and fermentation temperature, and some additional ingredients such as sugar or enzymes can be effective in flavor generation by yeasts or LAB (Buksa, 2020; Guerzoni et al., 2007; Pico et al., 2017; Rusinek et al., 2020; Thiele et al., 2002; Van Kerrebroeck et al., 2018; Winters et al., 2019; Xu et al., 2020).…”