Brazilian sourdough: microbiological, structural, and technological evolution

This work aimed to evaluate the lactic acid bacteria (LAB) and yeast growth substrate consumption production of organic acids and volatile compounds in the Brazilian sourdough. In addition, the impact of fermentation on the structural modifications of the dough was also analyzed by Fourier-transform infrared spectroscopy and by Scanning electron microscope. Sourdough evaluations revealed that major biochemical changes occurred until the third day: highest LAB growth, increased acidity, production of alcohol and carboxylic acids, and modifications in the amides I and II of gluten and starch hydrolysis. Between the third–fifth days occurred the disappearance of butanoic acid and formation of different esters. As shown by principal component analysis, sourdough became mature after the fifth day, revealing stabilization of biochemical and technological parameters, besides the significant presence of esters and carboxylic acids. Therefore, this work acknowledges that the Brazilian traditional sourdough requires at least 5 days of fermentation to obtain the ideal technological qualities and volatile compounds for bakery applications.