Reference Number: 89
Year: 2005
Link: Link to original paper
Lactic Acid Bacteria: Heterofermentative | Homofermentative
Yeast: Species
Summary
The production of sourdough bread can be traced back to ancient times. Sourdough is a mixture of flour and water that is fermented with lactic acid bacteria (LAB). Sourdough is an intermediate product and contains metabolically active yeast and LAB strains. The LAB that develop in the dough may originate from selected natural contaminants in the flour or from a starter culture containing one or more known species of LAB. Sourdough can be produced in bakeries or obtained from commercial suppliers. The microbial ecology of the sourdough fermentation is determined by ecological factors. Microbiological studies have revealed that more than 50 species of LAB, mostly species of the genus Lactobacillus, and more than 20 species of yeasts, especially species of the genera Saccharomyces and Candida, occur in this ecological niche. The sourdough microflora is composed of stable associations of lactobacilli and yeasts, in particular due to metabolic interactions. As shown for certain industrial sourdough processes, such microbial associations may endure for years, although the fermentation process runs under non-aseptic conditions. A reproducible and controlled composition and activity of the sourdough microflora is indispensable to achieve a constant quality of sourdough bread.
SIGNIFICANCE OF THIS STUDY
The study provides an overview of the microbial diversity within sourdough starters and their key role in creating the perfect sourdough loaf. The study highlights the specific interactions between lactic acid bacteria and yeasts that are responsible for the overall flavour and texture of sourdough bread and in addition, demystifies the science behind why it is nutritionally superior and more easily digested compared to fast fermented commercial breads.