Influence of Sourdough Lactic Acid Bacteria and Chemical Acidification on Acrylamide Formation in Bread

Abstract

In this study, lactic acid bacteria (LAB) from spontaneous fermented rye flour were isolated, identified and characterized by their acidification rate, carbohydrate metabolism and grow. The main properties of the isolated strains were evaluated: acidification rate, carbohydrate metabolism and growth. The isolated and characterized LAB were used for production of rye sourdough, and the influence of sourdough on rye-wheat bread quality and safety parameters (L- (+)-lactic acid, acrylamide (AA) formation) was evaluated. Also, comparative experiment by using L- (+)-lactic acid (LA) for rye-wheat bread preparation was performed. L. plantarum, P. acidilactici and L. curvatus, demonstrated high acidic tolerance, good grown at 30–37 °C, and versatile carbohydrate metabolism. When the isolated LAB strains were used for rye flour fermentation, they showed obvious acidification rates while excreting proteolytic and amylolytic enzymes. Fermented rye flour delayed bread staling, and there was a significant influence of type of dough acidification (with L-(+)-LA or LAB) and the amount of acidification agent used on most of the analyzed RWB quality and safety parameters. L. plantarum sourdough (5% and 15% by mass) decreases the AA content in rye-wheat bread samples (p < 0.0001), in opposite to dough acidification with L- (+)-LA. Finally, the selected Lactic acid bacteria can be recommended for reduction of AA content and improving the quality and safety of rye-wheat bread.