Rheological, textural and nutritional properties of gluten-free sourdough made with functionally important lactic acid bacteria and yeast from Nigerian sorghum

Abstract

Sorghum, being gluten-free, is often recommended as a safe food for celiac patients as gluten is associated with celiac disease. However, gluten absence in cereals causes technological inadequacies. Sourdough fermentation using functional starter cultures could produce desirable properties in gluten-free cereals. Sorghum flour was subjected to sourdough fermentation using functional lactic acid bacteria and yeast as starter cultures and their effects on the rheology, texture and nutritional properties of the sourdoughs were investigated. Pediococcus pentosaceus LD7 fermented sourdough had the highest storage modulus (G′) (3.07Pa) and loss modulus (G″) (6.23Pa), while P. pentosaceus SA8 sourdough had the least G′ (0.88Pa) and G″ (2.87Pa). Scanning electron micrograph of the sorghum sourdough breads revealed an intact and less porous cell structure in the samples containing starters in comparison to the control sample. The sourdough bread produced with P. pentosaceus SA8 and S. cerevisiae YC1 had the highest total dietary fibre (17.2%) but least protein content (4.9%). The starters modified the structure and nutrients of the sourdough where P. pentosaceus LD7 exhibited the most significant effect on the rheological properties. The study showed that the use of the selected starter cultures is useful in improving the structure and nutrient of sorghum-based gluten-free breads.