Probabilistic model for the spoilage wine yeast Dekkera bruxellensis as a function of pH, ethanol and free SO2 using time as a dummy variable

The present study uses a probabilistic model to determine the growth/no growth interfaces of the spoilage wine yeast Dekkera bruxellensis CH29 as a function of ethanol (10-15%, v/v), pH (3.4-4.0) and free SO2 (0-50mg/l) using time (7, 14, 21 and 30days) as a dummy variable. The model, built with a total of 756 growth/no growth data obtained in a simile wine medium, could have application in the winery industry to determine the wine conditions needed to inhibit the growth of this species. Thereby, at 12.5% of ethanol and pH3.7 for a growth probability of 0.01, it is necessary to add 30mg/l of free SO2 to inhibit yeast growth for 7days. However, the concentration of free SO2 should be raised to 48mg/l to achieve a probability of no growth of 0.99 for 30days under the same wine conditions. Other combinations of environmental variables can also be determined using the mathematical model depending on the needs of the industry. © 2013 Elsevier B.V.The research leading to these results received funding from the Spanish Government (project AGL2010-15494) and Junta de Andalucía (through financial support to the group AGR-125 and the project AGR-7755). F.N. Arroyo-López wishes to thank CSIC and the Spanish Government for his Ramón y Cajal postdoctoral research contract. M.E. Sturm would like to thank INTA for funds to support her doctoral studies.Peer Reviewe

A probabilistic model for the spoilage wine yeast Dekkera/Brettanomyces bruxellensis as a function of pH, ethanol and free SO2 using time as dummy variable

The present study uses a probabilistic model to determine the growth/no growth interfaces of the spoilage wine yeast Dekkera bruxellensis CH29 as a function of ethanol (10–15%, v/v), pH (3.4–4.0) and free SO2 (0–50 mg/l) using time (7, 14, 21 and 30 days) as a dummy variable. The model, built with a total of 756 growth/no growth data obtained in a simile wine medium, could have application in the winery industry to determine the wine conditions needed to inhibit the growth of this species. Thereby, at 12.5% of ethanol and pH 3.7 for a growth probability of 0.01, it is necessary to add 30 mg/l of free SO2 to inhibit yeast growth for 7 days. However, the concentration of free SO2 should be raised to 48 mg/l to achieve a probability of no growth of 0.99 for 30 days under the same wine conditions. Other combinations of environmental variables can also be determined using the mathematical model depending on the needs of the industry.Fil: Sturm, María Elena. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Arroyo López, F. N.. Instituto de la Grasa. Food Biotechnology Department; EspañaFil: Garrido Fernández, A.. Instituto de la Grasa. Food Biotechnology Department; EspañaFil: Querol, A.. Instituto de Agroquímica y Tecnología de los Alimentos; EspañaFil: Mercado, Laura Analia. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ramirez, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; ArgentinaFil: Combina, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentin