TY - JOUR T1 - Clarification by Vacuum Filtration of Grenache Must. Utilization of Free Amino Acids During Fermentation and Bottle-Aging of Wine JF - American Journal of Enology and Viticulture JO - Am J Enol Vitic. SP - 313 LP - 322 DO - 10.5344/ajev.1996.47.3.313 VL - 47 IS - 3 AU - Carmen Ancin AU - Belen Ayestaran AU - Julian Garrido Y1 - 1996/01/01 UR - http://www.ajevonline.org/content/47/3/313.abstract N2 - The principal nitrogen sources in musts are ammonium ions and amino acids. Their uptake and metabolization by Saccharomyces cerevisiae depend not only on the strain and the physiological conditions, but also on the physical and chemical properties of the medium. In this sense, suspended solids stimulate the fermentation and intervene in nitrogen metabolism. The aim of this study was to observe the influence of vacuum filtration of Grenache must on the utilization of amino acids and other nitrogen compounds during fermentation and bottle-aging of wine. The results show that in the first phase of fermentation (up to 50% sugar consumption) the basic amino acids, with a greater general amino acid permease (GAP) affinity, were excreted or showed less consumption in the filtered must, while in the second phase (from 50% sugar consumption until the end of fermentation) most amino acids were excreted to the medium. In the process of stabilization and bottle-aging of wine, the yeast in wine made from filtered must consumed the major part of amino acids of proteins. ER -