Natali HERNANDEZ PARADA

Résumé de la thèse

Bread is a traditional food around the world, prepared with flour and water as main raw material. Sourdough has been used traditionally on bakery industry as leavening agent since ancient times; this dough is a mixture of flour and water naturally fermented by lactic acid bacteria (LAB) and yeast that confer fermentative vitality and the necessary acidification to carry out the baking process. During sourdough fermentation, LAB, and yeasts together with endogen enzymes are responsible of the microbial metabolism and enzymatic hydrolysis of carbohydrates, phenolic compounds, lipids, and proteins. These biochemical changes have influence on texture, shelf life, nutritional benefits, and general flavor of bread. The use of starter consortia in sourdough fermentative processes has been shown to influence its sensory, nutritional, and functional properties. It has been reported that in some studies indigenous microbial isolates are used, however, in the majority the microbial strains used have been isolated from other food systems. Therefore, the use of the microbiota present in coffee and cocoa by-products is of interest, in addition, studies on their effect on the sourdough fermentation process have not yet been carried out. The objective of this research is to study the potential of the microbiota of cocoa and coffee by-products as starter of sourdough production.