The acidification properties and technological performance (dough elasticity and bread volume) of four individual lactic acid bacteria (LAB) starter cultures (Lactobacillus delbrueckii subsp. bulgaricus LB18; Lactobacillus delbrueckii subsp. bulgaricus CNRZ 737; Lactobacillus delbrueckii subsp. bulgaricus 2483; Lactobacillus helveticus LH30) were investigated in relation to dough and bread quality derived from a sourdough fermentation. A plain dough mixture (without LAB starter cultures) was used as a control against the sourdough systems with added cultures. The exopolysaccharide (EPS) producing LAB starter cultures significantly increased dough stickiness and extendibility compared with the plain dough system. Total EPS production by the LAB cultures during sourdough formation differed depending on the culture used (in the order of NCFB 2483 > Z737 > LB18 > LH30). The viscoelastic nature of the dough was increased with the use of LAB cultures. Bread volume significantly increased with the inclusion of EPS cultures. Bread staling (as determined by the extent of firming of bread) was reduced with the use of ropy cultures. Increased exopolysaccharide production during dough formation appeared to be associated with reduced staling and increased bread volume.

Practical Applications

Sourdough bread and cereal products have experienced increased attention from consumers for either health or sensorial reasons. The current research investigate the potential use of a selected range of exopolysaccharide producing starter strains in an attempt to characterise textural and sensorial qualities derived from ropy and nonropy lactic acid bacteria (LAB) starter cultures. The results indicate a clear potential for these LAB cultures in improving consumer quality and shelf-life stability of sourdough products.