Effect of fermentation with selected lactic acid bacteria strains on the molecular and technological properties of...

This study provides an in-depth investigation of the relationship between fermentation-induced molecular changes and techno-functional properties of sorghum flour, using three lactic acid bacteria (LAB) strains - Lactobacillus delbrueckii subsp. bulgaricus 1932, Leuconostoc spp. 4454, and Lacticaseibacillus casei 4339. Fermentation at 25 °C for 15 h induced significant molecular changes, including the reduction of low molecular weight fractions (∼0.7 kDa), and depolymerization of starch and fiber (HPSEC analysis). Proton mobility and relaxation analyses (¹H LR-NMR) revealed matrix breakdown and stronger water-biopolymer interactions. These molecular changes were closely associated with improved technological properties, including enhanced starch gelatinization (higher enthalpy changes, DSC) and better pasting properties. Changes in structure and molecular interactions likely contributed to the increased viscosity of sorghum, even in the absence of exopolysaccharide production. This study bridges the gap between molecular-level transformations with functional outcomes, providing insights into tailoring fermentation processes for the development of sustainable and innovative sorghum-based foods.