Unlocking Nutrient Accessibility through Sourdough Fermentation : the effect of sourdough on antinutrient reduction, protein digestibility and fibre functionality in bread

Sammanfattning

Sourdough fermentation is a traditional bread leavening method based on the synergistic, metabolic activity of lactic acid bacteria (LAB) and yeast in the dough. This complex process is highly dependent on various extrinsic factors such as fermentation duration and intrinsic factors such as endogenous enzyme activities. The aims of this literature review are to deepen the knowledge on the effect of sourdough fermentation on nutrient accessibility, with particular focus on the antinutrient quantities of phytic acid and tannin, as well as protein and fibre digestibility within the bread. To conduct the literature research keywords like wholegrain, antinutrients, digestibility and sourdough fermentation were used when searching for relevant scientific articles using databases such as Google Scholar, Web of Science and SLU library Primo. Key findings suggest that sourdough fermentation provides significant biochemical transformation of the dough through microbial enzymes and acidification by LAB, which activates grain endogenous enzymes. These changes result in reduction of phytic acid and tannin, which improves the bioavailability of minerals and protein. Protein digestibility increase due to reduction of antinutrients and because of solubilisation and depolymerisation of gluten. Additionally, the amount of fibre increases because of exopolysaccharide production by LAB and resistant starch formation. Conversion of insoluble to soluble fibre occurs, thereby fibre functionality is increased. Sourdough fermentation can improve the nutritional quality of bread. However, producing sourdough bread with a specific nutritional profile requires more research. It is necessary to understand how individual and combined fermentation factors influence nutrient quality and bioavailability within the bread.