Tronchoni Jordi, Gamero Amparo, Arroyo-López Francisco Noé, Barrio Eladio, Querol Amparo
Departamento de Biotecnología de Alimentos, Instituto de Agroquímica y Tecnología de los Alimentos, CSIC. P.O. Box 73, E-46100 Burjassot, Valencia, Spain.
Int J Food Microbiol. 2009 Sep 15;134(3):237-43. doi: 10.1016/j.ijfoodmicro.2009.07.004. Epub 2009 Jul 12.
Yeasts with a high fructose consumption capability are very important for winemakers to solve problems associated with sluggish or stuck fermentations causing undesirable sweetness in wines. In the present study, we analyze the kinetics of glucose and fructose consumption during wine fermentations performed at low (12 degrees C) and high (28 degrees C) temperatures by twelve different yeast strains belonging to the species Saccharomyces cerevisiae, S. bayanus var. uvarum, S. kudriavzevii as well as interspecific Saccharomyces hybrids. Different mathematical equations (sigmoid, exponential and linear decay functions) were used to fit, by means of linear and nonlinear regressions, the sugar degradation along the fermentative process. Temperature had an important influence on glucose and fructose consumption, and clearly different degradation profiles were observed at 12 and 28 degrees C. From the obtained equations, times to consume half and total of the initial glucose and fructose concentrations present in the must were calculated, allowing a quantitative comparison among yeasts in order to select the fastest fermentative yeast according to the fermentation temperature. In general, all yeasts assayed showed a slightly higher preference for glucose than fructose at both temperatures, confirming the glucophilic character of Saccharomyces wine yeasts. However, at low temperatures, some Saccharomyces yeasts showed a fructophilic character at the beginning of fermentation. This kind of studies can be very useful for the wine industry to select yeast strains with different glucose/fructose preferences.
具有高果糖消耗能力的酵母对于酿酒师解决与葡萄酒发酵迟缓或停滞相关的问题非常重要，这些问题会导致葡萄酒中出现不良的甜味。在本研究中，我们分析了12种不同酵母菌株在低温（12摄氏度）和高温（28摄氏度）下进行葡萄酒发酵时葡萄糖和果糖的消耗动力学，这些酵母菌株分别属于酿酒酵母、巴氏酵母变种、库德里亚夫齐酵母以及种间酿酒酵母杂交种。通过线性和非线性回归，使用不同的数学方程（S形、指数和线性衰减函数）来拟合发酵过程中糖的降解情况。温度对葡萄糖和果糖的消耗有重要影响，在12摄氏度和28摄氏度下观察到明显不同的降解曲线。根据得到的方程，计算了消耗葡萄汁中初始葡萄糖和果糖浓度一半和全部所需的时间，从而能够对酵母进行定量比较，以便根据发酵温度选择发酵最快的酵母。总体而言，在两个温度下，所有检测的酵母对葡萄糖的偏好都略高于果糖，这证实了酿酒酵母的嗜葡萄糖特性。然而，在低温下，一些酿酒酵母在发酵开始时表现出嗜果糖特性。这类研究对于葡萄酒行业选择具有不同葡萄糖/果糖偏好的酵母菌株非常有用。
