Showing papers by "Maria João Sousa published in 1991"

Malo‐alcoholic fermentation: the influence of operating conditions on the kinetics of deacidification

Abstract: Vinho Verde wines are typical of Portuguese wines, and have a high level of malic acid. Sometimes, the grape musts of such wines have too high a malate level, and this paper studies the possibility of using a strain of Schizosaccharomyces pombe to remove this excess of malate. The influence of malic acid concentration, ethanol concentration and aeration rate on the kinetics of malic acid utilization by a strain of S. pombe is studied. A linear model is developed that allows for the time control of final malic acid concentration. The maximum specific malic acid consumption rate (qm,max) is shown to increase in a linear relationship with initial malic acid concentration. For ethanol concentrations below 40 g l‐1 no significant change in the specific malate consumption rate (qm.max) is detected. Above this value, a drastic decrease is observed. Aeration also plays an important role in malo‐alcoholic fermentation. When no air is sparged in the fermentation medium, ethanol and qm,max are maximal. The ...