Development of symbiotic starters of lactic acid bacteria, propionic acid bacteria and yeast for sourdough for bread and bakery products and their probation in industrial conditions

¹ Department of Technology of Grain, Fodder, Bakery and Confectionery Products, University of Food Technologies, 26 Maritza Blvd., 4002, Plovdiv, Bulgaria
² Department of Biochemistry and Molecular Biology, University of Food Technologies, 26 Maritza boulevard, 4002, Plovdiv, Bulgaria
³ Department of Microbiology, University of Food Technologies, 26 Maritza boulevard, 4002, Plovdiv, Bulgaria
⁴ Department of Technology of Wine and Beer, University of Food Technologies, 26 Maritza boulevard, 4002, Plovdiv, Bulgaria

Abstract

Sourdough starter development includes examination of potential strains of lactic acid bacteria (LAB), propionic acid bacteria and yeasts, selection of suitable strains, development of combinations and examination of the relationships between the strains in each combination, selection of symbiotic combinations and their industrial probation to determine their qualities. Three sourdough starter combinations from selected lactobacilli (homo- and heterofermentative species) or selected lactobacilli and propionic acid bacteria were developed. The dynamics of the concentration of viable cells of the strains and the sourdough acidity in the back-slopping process up to the 96th hour were monitored. The rheological properties of the starter sourdoughs were characterized. The main dough obtained with sourdough was stronger, more elastic, the pieces of bread were taller. The developed sourdough starters were tested in the production of wheat, wheat-rye, spelt and spelled bread. The finished bread loaves had softer and lighter crumb, and pleasant and characteristic lactic acid aroma. It has been shown that the different bread types obtained with symbiotic starter sourdoughs had longer shelf life and increased microbiological safety. The best starter combination as well as the optimum concentration of starter sourdough for prevention of bacterial and fungal spoilage for each bread type has been determined.