The contribution of P. acidilactici, L. plantarum, and L. curvatus starters and L-(+)-lactic acid to the acrylamide content and quality parameters of mixed rye - Wheat bread

Lactic acid bacteria (LAB) from spontaneous rye sourdough were isolated, identified, and characterized by their growth, acidification rate, and carbohydrate metabolism. The isolated LAB were used for production of rye sourdough, and the influence of sourdough on mixed rye - wheat bread quality and acrylamide formation was evaluated. In addition, comparative studies by using acidification with L-(+)-lactic acid for mixed rye – wheat bread production were performed. Isolated LAB (P. acidilactici, L. plantarum, L. curvatus) demonstrated versatile carbohydrate metabolism, grown at 30 °C and 37 °C, and acidic tolerance. When the isolated strains were used for rye sourdough production, they showed good growth, acidification rates while excreting amylolytic and proteolytic enzymes. Rye sourdoughs delay bread staling, and there was a significant effect of type of dough acidification (with LAB or L-(+)-lactic acid) and the quantity of acidification agent used (5% or 15%) on most of the analyzed bread quality parameters. L. plantarum sourdough (added in the amount of 5% and 15%) decreased the acrylamide content in bread samples (p < 0.0001), unlike dough acidification with L-(+)-lactic acid. Thus the selected LAB could be recommended for improving the quality of bread, including the reduction of acrylamide content.