N Barrajón

Publications (3)4.81 Total impact

• Article: Enological properties in wild and commercial Saccharomyces cerevisiae yeasts: relationship with competition during alcoholic fermentation

  N. Barrajón, M. Arévalo-Villena, J. Úbeda, A. Briones
  [show abstract] [hide abstract]
  ABSTRACT: Commercial yeasts are widely used in winemaking to carry out the alcoholic fermentation; nevertheless, some wild strains may compete with them and even dominate the process. In this research, 21 prevailing wild strains isolated from inoculated musts were chosen in order to study the competition between them and commercial yeasts. Some biotechnological properties which could enhance their performance during the process were also studied, such as vitality, killer factor, resistance to high concentrations of sugar, ethanol and SO2 or trehalose and glycogen cell content. All yeasts, both commercial and wild strains, showed resistance to the killer toxin and they were all able to growth under adverse conditions. However, vitality and carbohydrate content were strain dependent in around 70% of the cases; the wild strain had a higher vitality and accumulated less trehalose than its commercial counterpart. KeywordsCommercial yeast–Wild yeast–Vitality–Co-fermentation–Trehalose
  World Journal of Microbiology and Biotechnology 04/2012; 27(11):2703-2710. · 1.53 Impact Factor
• Article: Co-inoculation of different Saccharomyces cerevisiae strains and influence on volatile composition of wines.

  N Barrajón, A Capece, M Arévalo-Villena, A Briones, P Romano
  [show abstract] [hide abstract]
  ABSTRACT: Wine is the result of the performance of different yeast strains throughout the fermentation in both spontaneous and inoculated processes. 22 Saccharomyces cerevisiae strains were characterized by microsatellite fingerprinting, selecting 6 of them to formulate S. cerevisiae mixed cultures. The aim of this study was to ascertain a potential benefit to use mixed cultures to improve wine quality. For this purpose yeasts behavior was studied during co-inoculated fermentations. Aromatic composition of the wines obtained was analyzed, and despite the fact that only one strain dominated at the end of the process, co-cultures released different concentrations of major volatile compounds than single strains, especially higher alcohols and acetaldehydes. Nevertheless, no significant differences were found in the type and quantity of the amino acids assimilated. This study demonstrates that the final wine composition may be modulated and enhanced by using suitable combinations of yeast strains.
  Food Microbiology 08/2011; 28(5):1080-6. · 3.28 Impact Factor
• Article: Ecological study of wine yeast in inoculated vats from La Mancha region

  N. Barrajón, M. Arévalo-Villena, L.J. Rodríguez-Aragón, A. Briones
  [show abstract] [hide abstract]
  ABSTRACT: Use of certain selected commercial yeast cultures has become widespread throughout the wine-making sector, but there was not any study about their effectiveness in Castilla-La Mancha region. This study sought to determine, whether the commercial yeast successfully displaced native yeasts during the fermentation process, or whether it was replaced by them. A total of 41 vats containing different grape varieties were sampled at different stages of fermentation, selecting 1640 isolated yeasts, which were characterized using molecular biology techniques (RFLP mtDNA). From results obtained, it can be concluded that inoculation of fermentation tanks with active dry yeasts does not guarantee their implantation during alcoholic fermentation. Indeed, these added strains may be scarce or even non-existent during the process.
  Food Control.