Population analysis of biofilm yeasts during fino sherry wine aging in the Montilla-Moriles D.O. region

• Published in: International journal of food microbiology Vol. 244; pp. 67 - 73
• Main Authors: Marin-Menguiano, Miriam, Romero-Sanchez, Sandra, Barrales, Ramón R., Ibeas, Jose I.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 06-03-2017; Elsevier BV
• Subjects: Acetaldehyde; Acetaldehyde - analysis; Age; Baking yeast; Biofilm; Biofilms; Biofilms - growth & development; Biological aging; DNA, Intergenic - genetics; Fermentation - physiology; Flor yeast; Food Microbiology; Food Storage - methods; Mycological Typing Techniques - methods; Polymorphism, Restriction Fragment Length; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - isolation & purification; Saccharomyces cerevisiae - metabolism; Sherry; Sherry wine; Spain; Velum; Wine; Wine - analysis; Wine - microbiology; Wineries; Wineries & vineyards; Wines; Yeast; Yeasts; Spain; Yeast; Biofilm; Biological aging; Saccharomyces cerevisiae; Sherry wine; Velum; Flor yeast
• DOI: 10.1016/j.ijfoodmicro.2016.12.019
• EISSN: 1879-3460
• ISSN: 0168-1605

Fino is the most popular sherry wine produced in southern Spain. Fino is matured by biological aging under a yeast biofilm constituted of Saccharomyces cerevisiae yeasts. Although different S. cerevisiae strains can be identified in such biofilms, their diversity and contribution to wine character have been poorly studied. In this work, we analyse the flor yeast population in five different wineries from the Montilla-Moriles D.O. (Denominación de Origen) in southern Spain. Yeasts present in wines of different ages were identified using two different culture-dependent molecular techniques. From 2000 individual yeast isolates, five different strains were identified with one of them dominating in four out of the five wineries analysed, and representing 76% of all the yeast isolates collected. Surprisingly, this strain is similar to the predominant strain isolated twenty years ago in Jerez D.O. wines, suggesting that this yeast is particularly able to adapt to such a stressful environment. Fino wine produced with pure cultures of three of the isolated strains resulted in different levels of acetaldehyde. Because acetaldehyde levels are a distinctive characteristic of fino wines and an indicator of fino aging, the use of molecular techniques for yeast identification and management of yeast populations may be of interest for fino wine producers looking to control one of the main features of this wine.
•Five different flor yeast strains were identified in the Montilla-Moriles D.O. region.•Most of the barrels analysed are pure cultures of a specific strain.•The main strain identified produces the lowest amount of acetaldehyde during aging.•A main strain prevails in flor yeast population in the two major fino wine D.O. regions.