Lourdes Soto Muñoz

By Dalia E. Miranda Castilleja, Jesús A. Aldrete Tapia, Sofía M. Arvizu Medrano, Montserrat Hernández Iturriaga, Lourdes Soto Muñoz and Ramón Á. Martínez Peniche

Criteria to select autochthonous yeast strains for their use in fermented beverages include their ability to dominate the media and to enhance desired sensorial characteristics and their inability to produce undesired compounds such as biogenic amines or off-odors. One of the key features in yeast selection is its Implantation, surpassing different stresses, and its fermentation performance, which requires setting up the process and monitoring it, involving important amount of resources. Methods to evaluate the tolerance of yeast strains are usually based in the qualitative measure of the growth of the microorganism in a medium containing the limiting compound after a specific time of incubation. However, studying strain growth through optical density measurements permits to estimate quantitative and comparable parameters providing an insight into the fitness of the cell to certain environment, lag phase duration, growth rate, and maximum population, among others. In the last decades, culture-independent methods have been used to evaluate the dynamic of microbial populations during fermentative process. In this chapter, a review of recent advances in the selection of fermentative yeasts as well as the utilization of kinetic evaluation and molecular strategies in conditions associated with fermented beverage for selecting yeast strains is presented.

Part of the book: Yeast

By Jesús Alejandro Aldrete-Tapia, Dalia Elizabeth Miranda-Castilleja, Sofia Maria Arvizu-Medrano, Ramón Álvar Martínez-Peniche, Lourdes Soto-Muñoz and Montserrat Hernández-Iturriaga

Fermented beverages are widely diverse around the world and their quality is largely based on the organoleptic characteristics developed by the metabolism of the microorganisms present during fermentation. In order to achieve controllable processes in fermented beverages along with organoleptic complexity, two divergent approaches have been followed in terms of inoculum development: (1) the inoculation of multiple microorganisms, intending to promote synergism and favor organoleptic complexity derived from the metabolic diversity, and (2) the genetic modification of a single strain with the intention that it performs multiple functions. In this chapter, we discuss these divergent approaches, their achievements and perspectives.

Part of the book: Frontiers and New Trends in the Science of Fermented Food and Beverages