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

STURM M.E.; ARROYO-LÓPEZ F.N.; GARRIDO FERNANDEZ A.; QUEROL A.; MERCADO L.; RAMIREZ M.L.; COMBINA M.

INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014 vol. 170 p. 83 - 90

0168-1605

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 dummy variable. The model, built with a total of 756 growth/no growth data obtained in a simil wine medium, has application to industry determining 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 up to 48 mg/l to achieve the same level of inhibition for 30 days at the same wine conditions. Other combinations of the environmental variables can also be determined by the mathematical model depending on the needs of the industry.